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 rep(i,n) for(ll i=0;i<(n);i++)
#define sz(x) int(x.size())
#define pb push_back
using ll=long long;
using P = pair<int,int>;
#define chmax(x,y) x = max(x,y)
const ll MOD=1000000007,MOD2=998244353,INF=1e18;



int main() {
    int S,W;
    cin>>S>>W;
    if(W>=S){cout<<"unsafe"<<endl;}
    else{cout<<"safe"<<endl;}
}