void setup() {
  // put your setup code here, to run once:
  
  pinMode(2, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);
  
}

void loop() {
  // put your main code here, to run repeatedly:
  int time = 200;
  for(int i=2;i<8;i=i+1){
    digitalWrite(i, HIGH);
    delay(time);
    digitalWrite(i, LOW);
  }

  for(int x=2;x>1;x=x-1){
    digitalWrite(x, HIGH);
    delay(time);
    digitalWrite(x, LOW);
  }
  
}