from itertools import *
def f(x, y, z, w):
    return (w or x or y) <= ((y or z) and x or y and (w or z))
for a in product([0, 1], repeat = 5):
    table = [(0, 0, 0, a[0]), (a[1], 1, 1, a[2]), (a[3], 1, a[4], 1)]
    if len(table) == len(set(table)):
        for p in permutations('xyzw'):
            if [f(**dict(zip(p, r))) for r in table] == [0, 0, 0]:
                print(p)