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)

#include<stdio.h>
#define N 2

int main(void){
  	void battle(int *, int *);
  	int T[N],A[N];
  
  	scanf("%d %d %d %d",&T[0], &T[1], &A[0], &A[1]);
  	//printf("%d %d %d %d\n",T[0], T[1], A[0], A[1]); //OK
  
  	battle(T,A);
  
  	return 0;
}

void battle(int *p1,int *p2){
  	
  	//int C = 0;printf("%d %d %d %d\n",*p1, *(p1 + 1), *p2,*(p2 + 1)); //OK
  	
	while(1){
    	*p2 -=  *(p1 + 1); //p1の攻撃
      	//printf("p2's rest is %d\n",*p2);
      
      	if(*p2 <= 0){
        	printf("yes\n");
          	break;
        }//C++;
      	*p1 -=  *(p2 + 1); //p2の攻撃
      	//printf("p1's rest is %d\n",*p1);	
      
      	if(*p1 <= 0){
        	printf("No\n");
          	break;
        }//C++; OK
    }
  	//printf("C = %d\n",C); //OK
}