There are S sheep and W wolves.

If the number of wolves is greater than or equal to that of sheep, the wolves will attack the sheep.

If the wolves will attack the sheep, print `unsafe`; otherwise, print `safe`.

Constraints

* 1 \leq S \leq 100
* 1 \leq W \leq 100

Input

Input is given from Standard Input in the following format:


S W


Output

If the wolves will attack the sheep, print `unsafe`; otherwise, print `safe`.

Examples

Input

4 5


Output

unsafe


Input

100 2


Output

safe


Input

10 10


Output

unsafe
n,m = map(int, raw_input().split(' '))
print 'unsafe' if n <= m else 'safe'