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 C (GCC 9.2.1) (judge verdict: Wrong Answer)

// Atcorder B-Battle

/*
高橋君 HP: A, Pow: B
青木君 HP: C, Pow: D
0以下で敗北
高橋君が勝ちで'Yes', 負けで'No'
1<= A,B,C,D <= 100
*/
#include <stdio.h>
void battle(int t_attack, int my_hp); // 戦闘
int main() {
  int a, b, c, d; // 変数宣言
  scanf("%d%d%d%d", &a, &b, &c, &d); // 標準入力

  if ((a/d)>(c/d)||(a%d)>(c%d)) {
    printf("Yes");
  } else {
    printf("No");
  }


//   for(int i=0; a>0&&c>0; ++i) { // 戦闘ループ
//   // printf("%d %d %d %d\n",a,b,c,d);
//     if (i%2==0) {
//       c-=b; // 高橋君→青木君 : 攻撃
//     } else {
//       a-=d; // 青木君→高橋君 : 攻撃
//     }
//   }
//   if (a<=0) { // 結果
//     printf("No\n");
//   } else {
//     printf("Yes\n");
//   }
  return 0;
}

// oh |ω・)