diff --git a/@bell/src/main.cpp b/@bell/src/main.cpp
index 1657350..775e6dd 100644
--- a/@bell/src/main.cpp
+++ b/@bell/src/main.cpp
@@ -1,49 +1,66 @@
 //
-// wirelessly connected cloud (Wireless Mesh Networking)
-// MIDI-like
-// spacial
-// sampler keyboard
+// wirelessly connected cloud (based on ESP-NOW, a kind of LPWAN?)
 //
 
 //
-// Forest all/around @ MMCA, Seoul
+// `hing @ dianaband studio, Seoul
 //
 
 //
-// 2020 10 14
+// 2021 02 15
+//
+//   this module will be an esp-now node in a group.
+//       like, a bird in a group of birds.
+//
+//   esp-now @ esp8266 w/ broadcast address (FF:FF:FF:FF:FF:FF)
+//       always broadcasting. everyone is 'talkative'.
 //
 
-//==========<configurations>===========
+// then, let it save a value in EEPROM (object with memory=mind?)
+
+//============<identities>============
+//
+#define MY_GROUP_ID       (11000)
+#define MY_ID             (MY_GROUP_ID + 1)
+#define MY_SIGN           ("BELL")
+#define ADDRESSBOOK_TITLE ("broadcast only")
+//
+//============</identities>============
+
+//==========<list-of-configurations>===========
+//
+// 'HAVE_CLIENT'
+// --> i have a client. enable the client task.
+//
+// 'SERIAL_SWAP'
+// --> UART pin swapped.
+//     you want this, when you want a bi-directional comm. to external client boards (e.g. teensy).
 //
 // 'DISABLE_AP'
-// --> disabling AP is for teensy audio samplers.
-//     they need this to reduce noise from AP beacon signals.
-//     but, then they cannot build-up net. by themselves.
-//     we need who can do AP..
-//     ==> TODO! just prepare some 'dummy' postmans around. w/ AP activated.
+// --> (questioning)...
 //
-// 'DISABLE_I2C_REQ'
-// --> a quirk.. due to bi-directional I2C hardship.
-//     ideally, we want to make this sampler node also speak.
-//     but, I2C doesn't work. maybe middleware bug.. we later want to change to diff. proto.
-//     for example, UART or so.
-//     ==> BEWARE! yet, still we need to take off this.. for 'osc' node.
-//
-// 'SET_ROOT'
-// 'SET_CONTAINSROOT'
-// --> for the network stability
-//     declare 1 root node and branches(constricted to 'contains the root')
-//     to improve the stability of the net
-//
-//==========</configurations>==========
+// 'REPLICATE_NOTE_REQ' (+ N_SEC_BLOCKING_NOTE_REQ)
+// --> for supporting wider area with simple esp_now protocol,
+//     all receipents will replicate NOTE msg. when they are newly appeared.
+//   + then, network would be flooded by infinite duplicating msg.,
+//     unless they stop reacting to 'known' req. for some seconds. (e.g. 3 seconds)
 
-//==========<preset>===========
-#define SET_CONTAINSROOT
-//==========</preset>==========
+// 'HAVE_CLIENT_I2C'
+// --> i have a client w/ I2C i/f. enable the I2C client task.
+//
+// 'ADDRESSBOOK_TITLE'
+// --> peer list limited max. 20.
+//     so, we might use different address books for each node to cover a network of more than 20 nodes.
+//
+//==========</list-of-configurations>==========
+//
+// (EMPTY)
+#define DISABLE_AP
+// #define REPLICATE_NOTE_REQ
 
-//============<gastank>============
+//============<bell>============
 #define BELL_HIT_KEY 105
-//============</gastank>===========
+//============</bell>===========
 
 //============<parameters>============
 //
@@ -68,30 +85,68 @@
 //
 //============</parameters>===========
 
+//============<board-specifics>============
+#if defined(ARDUINO_FEATHER_ESP32) // featheresp32
+#define LED_PIN 13
+#else
+#define LED_PIN 2
+#endif
+//============</board-specifics>===========
+
 //arduino
 #include <Arduino.h>
 
 //post & addresses
 #include "../../post.h"
 
+//vector
+#include <vector>
+std::vector<Note> recentNotes;
+
 //espnow
 #include <ESP8266WiFi.h>
 #include <espnow.h>
+AddressLibrary lib;
 
 //task
 #include <TaskScheduler.h>
 Scheduler runner;
 
+//
+#if defined(REPLICATE_NOTE_REQ)
+Note note_now = {
+  -1, // int32_t id;
+  -1, // float pitch;
+  -1, // float velocity;
+  -1, // float onoff;
+  -1, // float x1;
+  -1, // float x2;
+  -1, // float x3;
+  -1, // float x4;
+  -1 // float ps;
+};
+#define RECENT_NOTES_TIMEOUT (3000)
+static unsigned long last_note_time = 0;
+void recent_clear() {
+  //
+  if (millis() - last_note_time > RECENT_NOTES_TIMEOUT) {
+    recentNotes.clear();
+    Serial.println("recent list cleared");
+    last_note_time = millis();
+  }
+  //
+}
+Task recent_clear_task(100, TASK_FOREVER, &recent_clear, &runner, true);
+#endif
 //-*-*-*-*-*-*-*-*-*-*-*-*-
 // servo
 #include <Servo.h>
 
 #define SERVO_PIN D6
 Servo myservo;
-// #define HITTING_ANGLE 87
-#define HITTING_ANGLE 90
-#define RELEASE_ANGLE 60
-#define STABILIZE_ANGLE 53
+int hitting_angle = 90;
+int release_angle = 60;
+int stabilize_angle = 53;
 
 //
 extern Task hit_task;
@@ -117,32 +172,32 @@ void hit() {
   if (count % 3 == 0) {
     //
     myservo.attach(SERVO_PIN);
-    myservo.write(RELEASE_ANGLE);
+    myservo.write(release_angle);
     // servo_release_task.restartDelayed(200);
     //
   } else if (count % 3 == 1) {
     //
     myservo.attach(SERVO_PIN);
-    myservo.write(HITTING_ANGLE);
+    myservo.write(hitting_angle);
     // servo_release_task.restartDelayed(200);
     //
     Serial.print("bell, bell, bell! : ");
-    Serial.print(HITTING_ANGLE);
+    Serial.print(hitting_angle);
     Serial.println(" deg.");
     //
   } else {
     //
     myservo.attach(SERVO_PIN);
-    myservo.write(RELEASE_ANGLE);
+    myservo.write(release_angle);
     servo_release_task.restartDelayed(200);
     //
     Serial.print("release to .. : ");
-    Serial.print(RELEASE_ANGLE);
+    Serial.print(release_angle);
     Serial.println(" deg.");
     // start stablizing..
     pcontrol_new = true;
-    pcontrol_start = RELEASE_ANGLE;
-    pcontrol_target = STABILIZE_ANGLE;
+    pcontrol_start = release_angle;
+    pcontrol_target = stabilize_angle;
     pcontrol_task.restartDelayed(80);
     //
     control_count = 0;
@@ -181,13 +236,13 @@ void pcontrol() {
     // stand-by processes
     if (control_count % 2 == 0) {
       pcontrol_new = true;
-      pcontrol_start = STABILIZE_ANGLE;
-      pcontrol_target = RELEASE_ANGLE;
+      pcontrol_start = stabilize_angle;
+      pcontrol_target = release_angle;
       pcontrol_task.restartDelayed(300);
     } else if (control_count % 2 == 1) {
       pcontrol_new = true;
-      pcontrol_start = RELEASE_ANGLE;
-      pcontrol_target = STABILIZE_ANGLE;
+      pcontrol_start = release_angle;
+      pcontrol_target = stabilize_angle;
       pcontrol_task.restartDelayed(300);
     }
     //
@@ -201,148 +256,260 @@ void servo_release() {
   myservo.detach();
 }
 Task servo_release_task(0, TASK_ONCE, &servo_release);
+//*-*-*-*-*-*-*-*-*-*-*-*-*
 
-// mesh callbacks
-void receivedCallback(uint32_t from, String & msg) { // REQUIRED
-  Serial.print("got msg.: ");
-  Serial.println(msg);
-  //parse now.
-
-  //parse letter string.
-
-  // letter frame ( '[' + 30 bytes + ']' )
-  //    : [123456789012345678901234567890]
-
-  // 'MIDI' letter frame
-  //    : [123456789012345678901234567890]
-  //    : [KKKVVVG.......................]
-  //    : KKK - Key
-  //      .substring(1, 4);
-  //    : VVV - Velocity (volume/amp.)
-  //      .substring(4, 7);
-  //    : G - Gate (note on/off)
-  //      .substring(7, 8);
-
-  String str_key = msg.substring(1, 4);
-  String str_velocity = msg.substring(4, 7);
-  String str_gate = msg.substring(7, 8);
-
-  int key = str_key.toInt();
-  int velocity = str_velocity.toInt(); // 0 ~ 127
-  int gate = str_gate.toInt();
-
-  //is it for me, the bell?
-  if (key == BELL_HIT_KEY && gate == 1) {
-    hit_task.restartDelayed(10);
+//
+extern Task hello_task;
+static int hello_delay = 0;
+void hello() {
+  //
+  byte mac[6];
+  WiFi.macAddress(mac);
+  uint32_t mac32 = (((((mac[2] << 8) + mac[3]) << 8) + mac[4]) << 8) + mac[5];
+  //
+  Hello hello(String(MY_SIGN), MY_ID, mac32); // the most basic 'hello'
+  // and you can append some floats
+  static int count = 0;
+  count++;
+  hello.h1 = (count % 1000);
+  // hello.h2 = 0;
+  // hello.h3 = 0;
+  // hello.h4 = 0;
+  //
+  uint8_t frm_size = sizeof(Hello) + 2;
+  uint8_t frm[frm_size];
+  frm[0] = '{';
+  memcpy(frm + 1, (uint8_t *) &hello, sizeof(Hello));
+  frm[frm_size - 1] = '}';
+  //
+  esp_now_send(NULL, frm, frm_size); // to all peers in the list.
+  //
+  // MONITORING_SERIAL.write(frm, frm_size);
+  // MONITORING_SERIAL.println(" ==(esp_now_send/0)==> ");
+  //
+  if (hello_delay > 0) {
+    if (hello_delay < 100) hello_delay = 100;
+    hello_task.restartDelayed(hello_delay);
   }
 }
-void changedConnectionCallback() {
-  Serial.println(mesh.getNodeList().size());
-  // check status -> modify status LED
-  if (mesh.getNodeList().size() > 0) {
-    // (still) connected.
-    onFlag = false; //reset flag stat.
-    statusblinks.set(LED_PERIOD, 2, &taskStatusBlink_slowblink_insync);
-    // statusblinks.set(0, 1, &taskStatusBlink_steadyOff);
-    statusblinks.enable();
-    Serial.println("connected!");
+Task hello_task(0, TASK_ONCE, &hello, &runner, false);
+
+//task #0 : blink led
+extern Task blink_task;
+void blink() {
+  //
+  static int count = 0;
+  count++;
+  //
+  switch (count % 4) {
+  case 0:
+    digitalWrite(LED_PIN, LOW); // first ON
+    blink_task.delay(LED_ONTIME);
+    break;
+  case 1:
+    digitalWrite(LED_PIN, HIGH); // first OFF
+    blink_task.delay(LED_GAPTIME);
+    break;
+  case 2:
+    digitalWrite(LED_PIN, LOW); // second ON
+    blink_task.delay(LED_ONTIME);
+    break;
+  case 3:
+    digitalWrite(LED_PIN, HIGH); // second OFF
+    blink_task.delay(LED_PERIOD - 2* LED_ONTIME - LED_GAPTIME);
+    break;
+  }
+}
+Task blink_task(0, TASK_FOREVER, &blink, &runner, true); // -> ENABLED, at start-up.
+
+// on 'Note'
+void onNoteHandler(Note & n) {
+  //is it for me?
+  if (n.id == MY_GROUP_ID || n.id == MY_ID) {
     //
-    isConnected = true;
-    runner.addTask(nothappyalone_task);
-    nothappyalone_task.enable();
+    if (n.pitch == BELL_HIT_KEY) {
+      if (n.onoff == 1) {
+        hitting_angle = n.velocity;
+        release_angle = n.x1;
+        stabilize_angle = n.x2;
+        hit_task.restartDelayed(10);
+      }
+    }
   }
-  else {
-    // disconnected!!
-    statusblinks.set(0, 1, &taskStatusBlink_steadyOn);
-    statusblinks.enable();
-    //
-    isConnected = false;
-  }
-  // let I2C device know
-  /////
-  Serial.println("hi. client, we ve got a change in the net.");
-}
-void newConnectionCallback(uint32_t nodeId) {
-  Serial.println(mesh.getNodeList().size());
-  Serial.println("newConnectionCallback.");
-  changedConnectionCallback();
 }
 
+// on 'receive'
+void onDataReceive(uint8_t * mac, uint8_t *incomingData, uint8_t len) {
+
+  //
+  //MONITORING_SERIAL.write(incomingData, len);
+
+  //
+#if defined(HAVE_CLIENT)
+  Serial.write(incomingData, len); // we pass it over to the client.
+#endif
+
+  // open => identify => use.
+  if (incomingData[0] == '{' && incomingData[len - 1] == '}' && len == (sizeof(Hello) + 2)) {
+    Hello hello("");
+    memcpy((uint8_t *) &hello, incomingData + 1, sizeof(Hello));
+    //
+    MONITORING_SERIAL.println(hello.to_string());
+    //
+  }
+
+  // open => identify => use.
+  if (incomingData[0] == '[' && incomingData[len - 1] == ']' && len == (sizeof(Note) + 2)) {
+    Note note;
+    memcpy((uint8_t *) &note, incomingData + 1, sizeof(Note));
+    onNoteHandler(note);
+
+    //is it for me?
+    if (note.id == MY_GROUP_ID || note.id == MY_ID) {
+      hello_delay = note.ps;
+      if (hello_delay > 0 && hello_task.isEnabled() == false) {
+        hello_task.restart();
+      }
+    }
+
+    MONITORING_SERIAL.println(note.to_string());
+
+    #if defined(REPLICATE_NOTE_REQ)
+    last_note_time = millis(); //clear timer reset : the recent list holding (re)started
+    // check if this note is in the list?
+    bool check = false;
+    for (uint32_t idx = 0; idx < recentNotes.size(); idx++) {
+      if (recentNotes[idx].pitch == note.pitch && recentNotes[idx].id == note.id) {
+        check = true;
+      }
+    }
+    // if not, add this into the list and repeat!
+    if (check == false) {
+      //
+      recentNotes.push_back(note);
+      //
+      uint8_t frm_size = sizeof(Note) + 2;
+      uint8_t frm[frm_size];
+      frm[0] = '[';
+      memcpy(frm + 1, (uint8_t *) &note, sizeof(Note));
+      frm[frm_size - 1] = ']';
+      //
+      esp_now_send(NULL, frm, frm_size); // to all peers in the list.
+      //
+      MONITORING_SERIAL.print("repeat! ==> ");
+      MONITORING_SERIAL.println(note.to_string());
+      //
+    }
+
+    //EMERGENCY PATCH.HACK:
+    // original code is not intended for a BURST of notes.
+    // so, only 1 msg. will be repeated in 3 sec. all others will be simply ignored.
+    // to make a burst of msgs repeatible:
+    // --> make a list of recent 'pitches'
+    //     if there is any new msg. check if this is in the list, if not, add it & repeat, if yes, skip it.
+    //     after 3sec no new msg., the list will be flushed. every new msg. will reset timeout + save the list for extra. 3 sec.
+    #endif
+  }
+}
+
+// on 'sent'
+void onDataSent(uint8_t *mac_addr, uint8_t sendStatus) {
+  char buff[256] = "";
+  sprintf(buff, "Delivery failed! -> %02X:%02X:%02X:%02X:%02X:%02X",  mac_addr[0],  mac_addr[1],  mac_addr[2],  mac_addr[3],  mac_addr[4],  mac_addr[5]);
+  if (sendStatus != 0) MONITORING_SERIAL.println(buff);
+}
+
+//
 void setup() {
+
   //led
   pinMode(LED_PIN, OUTPUT);
 
-  //mesh
+  //serial
+  Serial.begin(115200);
+  delay(100);
+
+  //info
+  Serial.println();
+  Serial.println();
+  Serial.println("\"hi, i m your postman.\"");
+  Serial.println("-");
+  Serial.println("- my id: " + String(MY_ID) + ", gid: " + String(MY_GROUP_ID) + ", call me ==> \"" + String(MY_SIGN) + "\"");
+  Serial.println("- mac address: " + WiFi.macAddress() + ", channel: " + String(WIFI_CHANNEL));
+#if defined(HAVE_CLIENT)
+  Serial.println("- ======== 'HAVE_CLIENT' ========");
+#endif
+#if defined(SERIAL_SWAP)
+  Serial.println("- ======== 'SERIAL_SWAP' ========");
+#endif
+#if defined(DISABLE_AP)
+  Serial.println("- ======== 'DISABLE_AP' ========");
+#endif
+#if defined(HAVE_CLIENT_I2C)
+  Serial.println("- ======== 'HAVE_CLIENT_I2C' ========");
+#endif
+#if defined(REPLICATE_NOTE_REQ)
+  Serial.println("- ======== 'REPLICATE_NOTE_REQ' ========");
+#endif
+  Serial.println("-");
+
+  //wifi
   WiFiMode_t node_type = WIFI_AP_STA;
 #if defined(DISABLE_AP)
   system_phy_set_max_tpw(0);
   node_type = WIFI_STA;
 #endif
-  // mesh.setDebugMsgTypes(ERROR | DEBUG | CONNECTION);
-  mesh.setDebugMsgTypes( ERROR | STARTUP );
-  mesh.init(MESH_SSID, MESH_PASSWORD, &runner, MESH_PORT, node_type, MESH_CHANNEL);
+  WiFi.mode(node_type);
 
-  //
-  // void init(String ssid, String password, Scheduler *baseScheduler, uint16_t port = 5555, WiFiMode_t connectMode = WIFI_AP_STA, uint8_t channel = 1, uint8_t hidden = 0, uint8_t maxconn = MAX_CONN);
-  // void init(String ssid, String password, uint16_t port = 5555, WiFiMode_t connectMode = WIFI_AP_STA, uint8_t channel = 1, uint8_t hidden = 0, uint8_t maxconn = MAX_CONN);
-  //
-
-#if defined(SET_ROOT)
-  mesh.setRoot(true);
-#endif
-#if defined(SET_CONTAINSROOT)
-  mesh.setContainsRoot(true);
-#endif
-  //callbacks
-  mesh.onReceive(&receivedCallback);
-  mesh.onNewConnection(&newConnectionCallback);
-  mesh.onChangedConnections(&changedConnectionCallback);
-  Serial.println(mesh.getNodeList().size());
-
-  //tasks
-  runner.addTask(statusblinks);
-  statusblinks.enable();
-
-  //serial
-  Serial.begin(115200);
-  delay(100);
-  Serial.println("hi, postman ready.");
-#if defined(DISABLE_AP)
-  Serial.println("!NOTE!: we are in the WIFI_STA mode!");
-#endif
-
-  //understanding what is 'the nodeId' ==> last 4 bytes of 'softAPmacAddress'
-  // uint32_t nodeId = tcp::encodeNodeId(MAC);
-  Serial.print("nodeId (dec) : ");
-  Serial.println(mesh.getNodeId(), DEC);
-  Serial.print("nodeId (hex) : ");
-  Serial.println(mesh.getNodeId(), HEX);
-  uint8_t MAC[] = {0, 0, 0, 0, 0, 0};
-  if (WiFi.softAPmacAddress(MAC) == 0) {
-    Serial.println("init(): WiFi.softAPmacAddress(MAC) failed.");
+  //esp-now
+  if (esp_now_init() != 0) {
+    Serial.println("Error initializing ESP-NOW");
+    return;
   }
-  Serial.print("MAC : ");
-  Serial.print(MAC[0], HEX); Serial.print(", ");
-  Serial.print(MAC[1], HEX); Serial.print(", ");
-  Serial.print(MAC[2], HEX); Serial.print(", ");
-  Serial.print(MAC[3], HEX); Serial.print(", ");
-  Serial.print(MAC[4], HEX); Serial.print(", ");
-  Serial.println(MAC[5], HEX);
+  esp_now_set_self_role(ESP_NOW_ROLE_COMBO);
+  esp_now_register_send_cb(onDataSent);
+  esp_now_register_recv_cb(onDataReceive);
+  //
+  // Serial.println("- ! (esp_now_add_peer) ==> add a 'broadcast peer' (FF:FF:FF:FF:FF:FF).");
+  // uint8_t broadcastmac[6] = {0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF};
+  // esp_now_add_peer(broadcastmac, ESP_NOW_ROLE_COMBO, 1, NULL, 0);
 
-  // for instance,
+  AddressBook * book = lib.getBookByTitle(ADDRESSBOOK_TITLE);
+  if (book == NULL) {
+    Serial.println("- ! wrong book !! : \"" + String(ADDRESSBOOK_TITLE) + "\""); while(1);
+  }
+  for (int idx = 0; idx < book->list.size(); idx++) {
+    Serial.println("- ! (esp_now_add_peer) ==> add a '" + book->list[idx].name + "'.");
+#if defined(ESP32)
+    esp_now_peer_info_t peerInfo = {};
+    memcpy(peerInfo.peer_addr, book->list[idx].mac, 6);
+    peerInfo.channel = 0;
+    peerInfo.encrypt = false;
+    esp_now_add_peer(&peerInfo);
+#else
+    esp_now_add_peer(book->list[idx].mac, ESP_NOW_ROLE_COMBO, 1, NULL, 0);
+#endif
+  }
+  // (DEBUG) fetch full peer list
+  { PeerLister a; a.print(); }
+  //
+  Serial.println("-");
+  Serial.println("\".-.-.-. :)\"");
+  Serial.println();
 
-  // a huzzah board
-  // nodeId (dec) : 3256120530
-  // nodeId (hex) : C21474D2
-  // MAC : BE, DD, C2, 14, 74, D2
+#if defined(SERIAL_SWAP)
+  Serial.println("-      ======== 'SERIAL_SWAP' ========");
+  // a proper say goodbye.
+  Serial.println("\"bye, i will do 'swap' in 1 second. find me on alternative pins!\"");
+  Serial.println("\"    hint: osc wiring ==> esp8266(serial.swap) <-> teensy(serial3)\"");
+  Serial.println("-");
+  Serial.println("\".-.-.-. :)\"");
+  delay(1000);   // flush out unsent serial messages.
 
-  // a esp8266 board (node mcu)
-  // nodeId (dec) : 758581767
-  // nodeId (hex) : 2D370A07
-  // MAC : B6, E6, 2D, 37, A, 7
-
-  //i2c master
-  Wire.begin();
+  // moving...
+  Serial.swap(); // use RXD2/TXD2 pins, afterwards.
+  delay(100);    // wait re-initialization of the 'Serial'
+#endif
 
   //tasks
   runner.addTask(hit_task);
@@ -351,11 +518,7 @@ void setup() {
 }
 
 void loop() {
+  //
   runner.execute();
-  mesh.update();
-#if defined(ESP32)
-  digitalWrite(LED_PIN, onFlag); // value == true is ON.
-#else
-  digitalWrite(LED_PIN, !onFlag); // value == false is ON. so onFlag == true is ON. (pull-up)
-#endif
+  //
 }
diff --git a/puredata/radio_bell.pd b/puredata/radio_bell.pd
new file mode 100644
index 0000000..418d416
--- /dev/null
+++ b/puredata/radio_bell.pd
@@ -0,0 +1,35 @@
+#N canvas 625 33 450 324 12;
+#X obj 74 276 s NOTE;
+#X floatatom 291 201 5 0 0 0 release\ angle - - 0;
+#X floatatom 279 97 5 0 0 2 stabilizing\ angle - - 0;
+#X obj 291 225 s X1;
+#X obj 279 121 s X2;
+#X floatatom 137 70 5 0 0 2 hitting\ angle - - 0;
+#X obj 137 131 t b a b b;
+#X obj 74 235 pack 11001 105 f 1;
+#X obj 76 197 bng 15 250 50 0 empty empty empty 17 7 0 10 #fcfcfc #000000
+#000000;
+#X obj 163 281 print;
+#X obj 137 100 f;
+#X obj 16 63 bng 15 250 50 0 empty empty empty 17 7 0 10 #fcfcfc #000000
+#000000;
+#X obj 138 7 inlet;
+#X obj 254 52 init 55;
+#X obj 303 161 init 55;
+#X obj 138 32 f 92;
+#X connect 1 0 3 0;
+#X connect 2 0 4 0;
+#X connect 5 0 10 0;
+#X connect 6 0 8 0;
+#X connect 6 1 7 2;
+#X connect 6 2 1 0;
+#X connect 6 3 2 0;
+#X connect 7 0 0 0;
+#X connect 7 0 9 0;
+#X connect 8 0 7 0;
+#X connect 10 0 6 0;
+#X connect 11 0 5 0;
+#X connect 12 0 15 0;
+#X connect 13 0 2 0;
+#X connect 14 0 1 0;
+#X connect 15 0 5 0;