A=1 D=1 failure
    D=2 C=1 failure
        C=2 failure
        C=3 E=1 failure
            E=2 failure
            E=3 failure
            E=4 B=1 success
                B=2 success
                B=3 success
                B=4 failure
        C=4 E=1 failure
            E=2 failure
            E=3 failure
            E=4 failure
    D=3 C=1 failure
        C=2 failure
        C=3 failure
        C=4 E=1 failure
            E=2 B=1 success
                B=2 failure
                B=3 failure
                B=4 failure
            E=3 failure
            E=4 failure
    D=4 C=1 failure
        C=2 failure
        C=3 failure
        C=4 failure
A=2 D=1 failure
    D=2 failure
    D=3 C=1 failure
        C=2 failure
        C=3 failure
        C=4 E=1 B=1 failure
                B=2 failure
                B=3 failure
                B=4 failure
            E=2 failure
            E=3 failure
            E=4 failure
    D=4 C=1 failure
        C=2 failure
        C=3 failure
        C=4 failure
A=3 D=1 failure
    D=2 failure
    D=3 failure
    D=4 C=1 failure
        C=2 failure
        C=3 failure
        C=4 failure
A=4 D=1 failure
    D=2 failure
    D=3 failure
    D=4 failure