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)

function myin(){return require("fs").readFileSync("/dev/stdin", "utf8").trim();}

//0:何もしない  1:数値へ変換  2:半角SPで分割  3:改行で分割  4:半角SPで分割し、数値配列へ
//5:改行で分割し、数値配列へ  6:1文字に分割  7:1文字に分割し、数値配列へ
function myconv(i, no){
  switch(no){
    case 0: return i;
    case 1: return parseInt(i);
    case 2: return i.split(" ");
    case 3: return i.split("\n");
    case 4: return i.split(" ").map((a)=>Number(a));
    case 5: return i.split("\n").map((a)=>Number(a));
    case 6: return i.split("");
    case 7: return i.split("").map((a)=>Number(a));
  }}
function Main(input) {
  input = myconv(input, 4);
  S = input[0];
  W = input[1];

  if(S <= W) {
    console.log('unsafe');
  } else {
    console.log('safe');
  }
}
Main(myin());