const int min=9;
const int max=13;

void setup() {
  // put your setup code here, to run once:

for (int i= min; i <= max; i++) {
   pinMode(i, OUTPUT);
  }
}

void loop() {
  // put your main code here, to run repeatedly:

for (int i=min; i<=max; i++){
 digitalWrite(i, HIGH);
 delay(200);
}

for (int i=max; i>=min; i--){
  digitalWrite(i, LOW);
  delay(200);
}
}