int lampumerah = 10 ;
int lampukuning = 11 ;
int lampuhijau = 12 ;
void setup() {
  // put your setup code here, to run once:
pinMode(lampumerah, OUTPUT);
pinMode(lampukuning, OUTPUT);
pinMode(lampuhijau,OUTPUT);
}
void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(lampumerah, HIGH);
digitalWrite(lampukuning, LOW);
digitalWrite(lampuhijau, LOW);
delay(3000);
digitalWrite(lampumerah, LOW);
digitalWrite(lampukuning, HIGH);
digitalWrite(lampuhijau, LOW);
delay(1000);
digitalWrite(lampumerah, LOW);
digitalWrite(lampumerah, LOW);
digitalWrite(lampuhijau, HIGH);
delay(2000);
}