int Green=0;
int Yellow=1;
int Red=2;
void setup() {
  pinMode(Green, OUTPUT);
  pinMode(Yellow, OUTPUT);
  pinMode(Red, OUTPUT);
}

void loop() {
 digitalWrite(Green, HIGH);
 delay(1000);
 digitalWrite(Yellow, HIGH);
 delay(500);
 digitalWrite(Red, HIGH);
 delay(1000);
}