//-- set pin mode
void spinMode() {

  for (int x=6; x<=13; x++) {  // set output pinMode to deigital led pin 6 - 13

    pinMode(x, OUTPUT);

  }

}
//---- 
void setup() {

  spinMode();

}
//--- digital write high right hand To left hand
void rightToleft() {
  // ----- left
  for (int x=6; x<=13; x++) {  // set pinMode to deigital led pin 6 - 13

    digitalWrite(x, HIGH);  // write high , 1
    delay(100);

    digitalWrite(x, LOW);  // write low , 0
    delay(100);
  
  }
}
// ----- end left
//--- digital write high left hand To right hand
void leftToright() {

  for (int x=13; x>=6; x--) {  // set pinMode to deigital led pin 6 - 13

    digitalWrite(x, HIGH);  // write high , 1
    delay(100);

    digitalWrite(x, LOW);  // write low , 0
    delay(100);
  } 
}
// ----- end right 

void loop() {

  rightToleft();
  leftToright();
  
}
//--- end program