public class Ampel {
    static int gruen = 1;
    static int gelb = 2;
    static int rot = 3;
    static int rotGelb = 4;
    static int farbe;
    static int wartezeit = 5000;

    public static void main(String[] args){
        machAmpeldinge();
    }

    public static void wechsleGruen(){
        try{
            Thread.sleep(5000);
            }catch(InterruptedException ex) {
                Thread.currentThread().interrupt();
            }
        farbe = rotGelb;
        if(farbe == 4){
            System.out.println("rotGelb");
        }
        try{
            Thread.sleep(5000);
            }catch(InterruptedException ex) {
                Thread.currentThread().interrupt();
            }
        farbe = gruen;
        if(farbe == 1){
            System.out.println("gruen");
        }

    }
    public static void wechsleGelb(){
        try{
            Thread.sleep(5000);
            }catch(InterruptedException ex) {
                Thread.currentThread().interrupt();
            }
        farbe = gelb;
        if(farbe == 2){
            System.out.println("gelb");
        }
    }
    public static void wechsleRot(){
        try{
            Thread.sleep(5000);
            }catch(InterruptedException ex) {
                Thread.currentThread().interrupt();
            }
        farbe = rot;
        if(farbe == 3){
            System.out.println("rot");
        }
    }
    public static void machAmpeldinge(){
        while(true){
            wechsleGruen();
            wechsleGelb();
            wechsleRot();
        }
    }
}