void setup() {
  // put your setup code here, to run once:
pinMode(9, OUTPUT);
pinMode(8, OUTPUT);
pinMode(7, OUTPUT);
digitalWrite(9,0);
digitalWrite(8,0);
digitalWrite(7,0);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(9,1);
delay(4000);
digitalWrite(9,0);
delayMicroseconds(1000);
digitalWrite(8,1);
delay(4000);
digitalWrite(8,0);
delayMicroseconds(1000);
digitalWrite(7,1);
delay(5000);
digitalWrite(7,0);
delay(1000);
}