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.util.*;

//update 2020/1/1 23:01

public class Main{

  static Scanner sc = new Scanner(System.in);
  static StringBuilder sb = new StringBuilder();

  public static void main(String[] args) {

    int S = nextInt();
    int W = nextInt();

    if(W>=S){
      System.out.println("unsafe");
    }
    else{
      System.out.println("safe");
    }
    //

  }
  /*
    static String toSmall(String s){
      char c = s.charAt(0);
      //if(Character.isUpperCase(c)){
      if(c<=90){
        c += 32;
      }
      return String.valueOf(c);
    }
    static String toBig(String s){
      char c = s.charAt(0);
      //if(Character.isLowerCase(c)){
      if(c>=97){
        c -= 32;
      }
      return String.valueOf(c);
    }
  */

  static String toSmall(String s){
    return s.toLowerCase();
  }

  static String toBig(String s){
    return s.toUpperCase();
  }

  static String next(){
    return sc.next();
  }

  static int nextInt(){
    return Integer.parseInt(sc.next());
  }

  static long nextLong(){
    return Long.parseLong(sc.next());
  }

  static double nextDouble(){
    return Double.parseDouble(sc.next());
  }

  static String[] splitString(String s){
    return s.split("");
  }

  static char[] splitChar(String s){
    return s.toCharArray();
  }

  static int charToInt(char a){
    return a - 48;
  }

////////////////////////////////////////////
  public static int max(int[] a){
    int lng = a.length;
    int max = a[0];
    for(int i=1;i<lng;i++){
      max = Math.max(max,a[i]);
    }
    return max;
  }
  public static long max(long[] a){
    int lng = a.length;
    long max = a[0];
    for(int i=1;i<lng;i++){
      max = Math.max(max,a[i]);
    }
    return max;
  }
////////////////////////////////////////////

////////////////////////////////////////////
  public static int min(int[] a){
    int lng = a.length;
    int min = a[0];
    for(int i=1;i<lng;i++){
      min = Math.min(min,a[i]);
    }
    return min;
  }
  public static long min(long[] a){
    int lng = a.length;
    long min = a[0];
    for(int i=1;i<lng;i++){
      min = Math.min(min,a[i]);
    }
    return min;
  }
////////////////////////////////////////////

}