void setup() {
pinMode(3,OUTPUT);
pinMode(7,OUTPUT);
pinMode(9,OUTPUT);
  // put your setup code here, to run once:

}

void loop() {
digitalWrite(3,HIGH);
delay(4000);
digitalWrite(7,HIGH);
delay(5000);
digitalWrite(9,HIGH);
delay(7000);
digitalWrite(3,LOW);
delay(4000);
digitalWrite(7,LOW);
delay(5000);
digitalWrite(9,LOW);
delay(7000);
  // put your main code here, to run repeatedly:

}