int Count = 6;
int leds[] = { 2, 3, 4, 5, 6, 7};
void setup() {
  for (int Pin = 0; Pin < Count; Pin++) {
    pinMode(leds[Pin], OUTPUT);
  }
}
void loop() {
  for (int Pin = 0; Pin < Count; Pin++) {
    digitalWrite(leds[Pin], 1);
    delay(100);
    digitalWrite(leds[Pin], 0);
  }
  for (int Pin = Count ; Pin >= 0; Pin--) {
    digitalWrite(leds[Pin], 1);
    delay(100);
    digitalWrite(leds[Pin], LOW);
  }
}