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 f(i,s,e) for(int i=s;i<e;i++)
#define rf(i,s,e) for(int i=e;i>=s;i--)
#define fr first
#define sc second
#define pb push_back
#define  vii vector<int>
#define vll vector<ll>
#define vpii vector<pair<int ,int >>
#define vpll vector<pair<ll, ll> >
#define  pii pair<int,int>
const long mod =998244353;
const int N = 2e3+5;
const long long inf= 1e18;

ll gcd(ll a ,ll b){if(b==0) return a;return gcd(b,a%b);}
ll mul(ll a ,ll b){return (a%mod * b%mod )%mod;}
ll mpower(ll a, ll b){if(b==0) return 1;ll temp=mpower(a,b/2);if(b%2==0){return mul(temp,temp);}else{	return mul(mul(temp,temp) , a);}}
ll inv(ll a){return mpower(a,mod-2);}
ll ncr(ll n, ll r){if(r==0)return 1;ll ans=n%mod;ans=mul(ans,ncr(n-1,r-1));ans=mul(ans,inv(r));	return ans;}
ll power(ll a, ll b){if(b==0) return 1;ll temp=power(a,b/2);if(b%2==0)return temp*temp;else return temp*temp*a;}

string str;
ll nb,ns,nc,p_b,ps,pc,r;
ll b=0,c=0,s=0;

bool isp(ll ans)
{
     ll b_t=b*ans, c_t=c*ans,s_t=s*ans;
     ll k=0;
     if(b_t>nb)k+=(b_t-nb)*p_b;
     if(c_t>nc)k+=(c_t-nc)*pc;
     if(s_t>ns)k+=(s_t-ns)*ps;
    return k<=r;
    
}
void solve()
{
    ll s,w;cin>>s>>w;
    if(w>=s)cout<<"unsafe"<<endl;
    else cout<<"safe"<<endl;
    
} 

int main()
{
	ios_base :: sync_with_stdio(0);cin.tie(0);cout.tie(0);
    int t=1;
    while(t--)
    {
        solve();
    }
}