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



if s <= w:

  print('unsafe')

else:

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

if w >= s:

    print('unsafe')

else:

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

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

-if s <= w: +if w >= s: