问java如何克服多重继承和菱形问题

EN

interface Alpha{
    public default int methodA() {
        int result=0;
        System.out.println("Print from Alpha methodA");
        return result+4;
    }
}

//**********************************

interface Betta extends Alpha {
    public default int methodA() {
        int result=0;
        System.out.println("Print from Betta methodA");
        return result+8;
    }
}
//*******************************

interface Gamma extends Alpha {
    public default int methodA() {
        int result=0;
        System.out.println("Print from Gamma methodA");
        return result+16;
    }
}

public class Delta implements Betta,Gamma {
    public static void main(String args[]) {
    // TODO Auto-generated method stub

    Delta cObj=new Delta();
    cObj.methodA();
}