for a in ['A', 'B', 'C', 'D', 'E']:
    for b in ['A', 'B', 'C', 'D', 'E']:
        for c in ['A', 'B', 'C', 'D', 'E']:
            for d in ['A', 'B', 'C', 'D', 'E']:
                print(a, b, c, d)