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: Time Limit Exceeded)

function Main(input) {
	input = input.split(" ");
	var tHP = parseInt(input[0], 10);
	var tAT = parseInt(input[1], 10);
	var aHP = parseInt(input[2], 10);
	var aAT = parseInt(input[3], 10);

while(true){
aHP =  aHP  -  tAT 
if ( aHP <= 0 ){console.log('yes'); return}
tHP =  tHP  -  aAT 
if ( tHP <= 0 ){console.log('No'); return}



}
}
Main(require("fs").readFileSync("/dev/stdin", "utf8"));