S,W=(int(x) for x in input().split())

 

if S <= W:

  print('unsafe')

else:

  print('safe')
S,W = list(map(int,input().split()))



if S <= W:

  print('unsafe')

else:

  print('safe')
S, W = (int(x) for x in input().split())
if S <= W:
    print("unsafe")
else:
    print("safe")

S, W = list(map(int, input().split()))
if S <= W:
    print("unsafe")
else:
    print("safe")

-S, W = (int(x) for x in input().split()) +S, W = list(map(int, input().split()))