print("x y z w")
for x in range(2):
for y in range(2):
for z in range(2):
for w in range(2):
f = (not(x <= z) or (y == w) or y)
if f == 0:
print(x, y, z, w)
cHJpbnQoInggeSB6IHciKQpmb3IgeCBpbiByYW5nZSgyKToKICAgIGZvciB5IGluIHJhbmdlKDIpOgogICAgICAgIGZvciB6IGluIHJhbmdlKDIpOgogICAgICAgICAgICBmb3IgdyBpbiByYW5nZSgyKToKICAgICAgICAgICAgICAgIGYgPSAobm90KHggPD0geikgb3IgKHkgPT0gdykgb3IgeSkKICAgICAgICAgICAgICAgIGlmIGYgPT0gMDogCiAgICAgICAgICAgICAgICAgICAgcHJpbnQoeCwgeSwgeiwgdykK
x y z w
(0, 0, 0, 1)
(0, 0, 1, 1)
(1, 0, 1, 1)