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>
using namespace std;
#define ll long long
#define forin(i,a,b) for(long long i=a;i<=b;i++)
#define fio ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define pb push_back
int main()
{
    // #ifndef ONLINE_JUDGE
    //    freopen ("input.txt" , "r" , stdin);
	// 	// freopen ("OUTPUT.txt" , "w" , stdout);
	// #endif
    fio;
    ll s,w;
    cin>>s>>w;
    if(w>=s)
    {
        cout<<"unsafe";
    }
    else
    cout<<"safe";
    cout<<endl;
    return 0;
}