void setup() {
  // put your setup code here, to run once:
pinMode(7, OUTPUT);
pinMode(3, OUTPUT);
pinMode(0, OUTPUT);
}

void loop() {
digitalWrite(7, HIGH);
delay(3000);
digitalWrite(3, HIGH);
delay(1000);
digitalWrite(0, HIGH);
digitalWrite(7, LOW);
digitalWrite(3, LOW);
delay(3000);
digitalWrite (3, HIGH);
digitalWrite (0, LOW);
delay (1000);
digitalWrite(3, LOW);


}