s, w = list(map(int, input().split()))

if w >= s:

    print('unsafe')

else:

    print('safe')
s, w = map(int, input().split())

print('unsafe') if w >= s else print('safe')

s, w = list(map(int, input().split()))
if w >= s:
    print("unsafe")
else:
    print("safe")

s, w = map(int, input().split())
print("unsafe") if w >= s else print("safe")

-s, w = list(map(int, input().split())) -if w >= s: -    print("unsafe") -else: -    print("safe") +s, w = map(int, input().split()) +print("unsafe") if w >= s else print("safe")