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) {
		try(Scanner scan = new Scanner(System.in)){
			
			int S = scan.nextInt();
			int W = scan.nextInt();
			System.out.println(W>=S?"unsafe":"safe");
		}
		
		
	}
		

}
