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)

#pragma GCC optimize("Ofast",3,"inline")
#include<bits/stdc++.h>
using namespace std;
#define fir first
#define sec second
#define m_p make_pair
#define y1 ygftgfgcdtfgxffgx
#define y2 yfdsesgvtyghftfvv
#define x1 xvyr6cf6fgcfgf676
#define x2 xcr6rfc5r66y6r6fr
#define up_bound upper_bound
#define low_bound lower_bound
#define next_per next_permutation
#define pb push_back
#define i_to_s to_string
typedef priority_queue<int> p_queue;
typedef priority_queue<int, vector<int>, greater<int> > min_p_queue;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
int mon[20]={31,28,31,30,31,30,31,31,30,31,30,31};
ll gcd(ll x,ll y){return ((y==0)?x:gcd(y,x%y));}
ll a,b;
int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
//	freopen(".in","r",stdin);
//	freopen(".out","w",stdout);
	cin>>a>>b;
	if(a<=b)cout<<"unsafe";
	else cout<<"safe";
	return 0;
}