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 Scanner(input) {
	var self = this;
	self.itemNo = 0;
	self.orgStr = input;
	self.splitedStrs = (function(target) {
		var result = [];
		var target = target.replace(/[\n \t]+/g, " ");
		var strs = target.split(" ");
		for (var i = 0, len = strs.length; i < len; i++) {
			result.push(strs[i]);
		}
		return result;
	}(input));

	self.next = function() {
		var result = self.splitedStrs[self.itemNo];
		self.itemNo++;
		return (result != null) ? result : null;
	}

	self.nextInt = function() {
		var result = self.splitedStrs[self.itemNo];
		self.itemNo++;
		return (result != null) ? parseInt(result) : null;
	}

	self.nextBigDecimal = function() {
		var result = self.splitedStrs[self.itemNo];
		self.itemNo++;
		return (result != null) ? parseFloat(result) : null;
	}
	
	self.nextByte = function() {
		var result = self.splitedStrs[self.itemNo];
		self.itemNo++;
		return (result != null) ? new Int8Array(result) : null;
	}

}

function Main(sc) {

	var S = sc.nextInt();
	var W = sc.nextInt();
	
	console.log((W >= S) ? "unsafe" : "safe");
}
Main(new Scanner(require("fs").readFileSync("/dev/stdin", "utf8")));
// Main(new Scanner("10 1 2 5 3 4 6 7 3 2 4 1 2 2 3 3 4 4 5 3 6 6 7 1 8 8 9 9 10"));

// var str1 = sc.next(); // Stringで取得
// var int1 = sc.nextInt(); // intで取得
// var bd1 = sc.nextBigDecimal(); // BigDecimalで取得
// var byte1 = sc.nextByte(); // byteで取得
// for (var i = 0; i < 1000000000; i++) var toDelay = "aaa"; // 1000msくらいの遅延
// console.log(wrtnNos); return;