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)

/*                        ______
 _______   /\     |``\   |        |  /
    |     /  \    |__/   |____    |/
    |    / _ _\   |  \   |        |\
    |   /      \  |   \  |______  |  \

            Dept. of CSE
        Comilla  University

*/
#include<bits/stdc++.h>
#define pi 2*acos(0.0)
#define ll long long
#define FIO ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define Node struct node
#define spc " "
#define  E  2.71828182845904523536
#define pb push_back
#define pp pop_back
#define valid(nx,ny) nx>=0 && nx<n && ny>=0 && ny<m
#define ee endl
#define pii pair<int,int>
#define infinity 10000000000000000
#define mod 1000000007
int fx[]={0,0,+1,-1};
int fy[]={+1,-1,0,0};

using namespace std;
///check n=1;
///check corner case;
const int maX=1e5+1;
vector<ll>Graph[maX],cost[maX];
ll visit[maX];


int main()
{
   ll w,s;
   cin>>s>>w;
   if(w>=s)cout<<"unsafe"<<endl;
   else cout<<"safe"<<endl;
return 0;
}