from itertools import *
def f(x, y, z, w):
    return w <= ((x <= z) <= y)
for a1, a2, a3, a4, a5, a6, a7 in product([0, 1], repeat = 7):
    table = [(a1, a2, 0, 1), (a3, 0, 1, a4), (a5, a6, a7, 0)]
    if len(table) == len(set(table)):
        for p in permutations('wyxz'):
            if [f(**dict(zip(p, r))) for r in table] == [0, 0, 0]:
                print(p)