void setup(){
  
  pinMode(7, OUTPUT); //red
  pinMode(8, OUTPUT);  //green
  pinMode(9, OUTPUT); //yellow
  
}
void loop(){
digitalWrite(7, HIGH);
 delay(600);
digitalWrite(7, LOW);
  
digitalWrite(8, HIGH);
delay(200);
digitalWrite(8, LOW);
  
  digitalWrite(9, HIGH);
delay(100);
  digitalWrite(9, LOW);
  
  
}