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: Accepted)

#include <bits/stdc++.h>
#define F first
#define S second
#define pb push_back
#define mp make_pair
#define nl '\n'

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef pair<int , int> pi;


int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);
	int s, w;
	cin>>s>>w;
	if(w >= s) 
	{
		cout<<"unsafe\n";
	}
	else
	{
		cout<<"safe\n";
	}
	
	return 0;
}