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>
#include<stdlib.h>

int main(void){
   int i,A,B,C,D,E,F;

   scanf("%d %d %d %d",&A,&B,&C,&D);

   if((1<=A)&&(A<=100)&&(1<=B)&&(B<=100)&&(1<=C)&&(C<=100)&&(1<=D)&&(D<=100)){
      E=C-B;
      if(E<=0){
      printf("Yes");
      return 0;
      }
      F=A-D;
      if(F<=0){
      printf("No");
      return 0;
      }
      
      for(i=0;i<20;i++){
      E=E-B;
            if(E<=0){
      printf("Yes");
      return 0;
      }
      F=F-D;
            if(F<=0){
      printf("No");
      return 0;
      }
      }}
      }