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>

void main(){
int a,b,c,d;
int i;
scanf("%d %d %d %d",&a,&b,&c,&d);
while(a>0 || c>0)
{
c-=b;
if(c<=0){i=0; break;}
a-=d;
if(a<=0){i=1; break;}

}
if(i==0)printf("Yes\n");
if(i==1)printf("No\n");
}