

def main():

 

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

    if S<=W:

        print("unsafe")

    else:

        print("safe")

    



if __name__ == '__main__':

    main()



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

answer="safe"

if S<=W:

    answer="unsafe"

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


if __name__ == "__main__":
    main()

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

-def main(): -    S, W = list(map(int, input().split())) -    if S <= W: -        print("unsafe") -    else: -        print("safe") - - -if __name__ == "__main__": -    main() +S, W = list(map(int, input().split())) +answer = "safe" +if S <= W: +    answer = "unsafe" +print(answer)