Problem:
Score : 100 points

Problem Statement

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.

Sample Input 1

4 5

Sample Output 1

unsafe

There are four sheep and five wolves. The number of wolves is not less than that of sheep, so they will attack them.

Sample Input 2

100 2

Sample Output 2

safe

Many a sheep drive away two wolves.

Sample Input 3

10 10

Sample Output 3

unsafe

Solution in JavaScript (Node.js 12.16.1) (judge verdict: Accepted)

"use strict";

function main(arg) {
    //    console.log(arg.trim().split("\n"));
    let ary = arg.trim().split(" ").map(n => Number(n));
    let sheep = ary.shift();
    let wolf = ary.shift();
    console.log(wolf >= sheep ? 'unsafe' : 'safe');

}
main(require('fs').readFileSync('/dev/stdin', 'utf8'));