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 (Clang 10.0.0) (judge verdict: Accepted)

#include <stdio.h>

int main()
{
    int s;
    int w;

    do{
        scanf("%d", &s);

    }while(s<0 || s>100);

    do{
        scanf("%d", &w);

    }while(w<0 || w>100);

    if(w>=s){
        printf("%s\n", "unsafe");
    } else {
    printf("%s\n", "safe");
    }

    return 0;
}