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 "bits/stdc++.h"
using namespace std;

int main() {
	int a, b, c, d, ans;
	cin >> a >> b >> c >> d;
	while (1) {
		c -= b;
		if (c <= 0) {
			ans = 0;
			break;
		}
		a -= d;
		if (a <= 0) {
			ans = 1;
			break;
		}
	}
	if (ans) {
		cout << "No" << endl;
	}
	else {
		cout << "Yes" << endl;
	}
}