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 Java (OpenJDK 11.0.6) (judge verdict: Accepted)

import java.io.*;
import java.util.*;

/**
 * Created by Ayushi on 26 Apr 2020.
 * Problem:
 * Round:
 */

public class Main {
    public static void main(String[] args) throws IOException {
        StringTokenizer st;
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        st = new StringTokenizer(br.readLine(), " ");
        int s = Integer.parseInt(st.nextToken());
        int w = Integer.parseInt(st.nextToken());
        br.close();
        System.out.println(w >= s ? "unsafe":"safe");
    }
}