int btngreen = 13;
int ledred = 12;
int ledyellow = 11;
int ledgreen = 10;

int statebtn = 0; 
int statebtnTerakhir = 0;
int ledSaatIni = 0; 

void setup() {
  // put your setup code here, to run once:
  pinMode(btngreen, INPUT_PULLUP); 
  pinMode(ledred, OUTPUT);
  pinMode(ledyellow, OUTPUT);
  pinMode(ledgreen, OUTPUT);

  digitalWrite(ledred, LOW);
  digitalWrite(ledyellow, LOW);
  digitalWrite(ledgreen, LOW);
}

void loop() {
  // put your main code here, to run repeatedly:
  int statebtn = digitalRead(btngreen);

  if (statebtn == HIGH && statebtnTerakhir == LOW) {
    ledSaatIni++;
    if (ledSaatIni > 3){
      ledSaatIni = 1;
    }
    delay(500); 

    digitalWrite(ledred, LOW);
    digitalWrite(ledyellow, LOW);
    digitalWrite(ledgreen, LOW);

    if (ledSaatIni == 1) {
      digitalWrite(ledred, HIGH);
    } else if (ledSaatIni == 2) {
      digitalWrite(ledyellow, HIGH);
    } else if (ledSaatIni == 3) {
      digitalWrite(ledgreen, HIGH);
    }
  }
  statebtnTerakhir = statebtn; 
}