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
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int S = sc.nextInt();
		int W = sc.nextInt();
		sc.close();
		if(W>=S) {
			System.out.println("unsafe");
		}else {
			System.out.println("safe");
		}

	}

}