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 int           long long
#define S             second
#define F             first
#define pb            push_back
#define all(c)        (c).begin(),(c).end()
#define rall(c)       (c).rbegin(),(c).rend() 
#define lb            lower_bound
#define si(c)         (int)((c).size())
#define lcm(a, b)      (a * (b / __gcd(a,b)))  
#define inf           (long long )(1e18+1)
#define endl          '\n'
#define mp            make_pair
#define time(s)       (double(clock()-s)/double(CLOCKS_PER_SEC))
#define debug(args...)    _F(#args, args)
#define vi            std::vector<int>
#define pii           pair<int, int> 
#define vpi           vector<pii>

clock_t start;
mt19937_64 rng(chrono::system_clock::now().time_since_epoch().count());

template<typename T> void _F(const char *name, T arg1){
    cerr << name << " = " << arg1 << endl;
}
template<typename T, typename... Args> void _F(const char *names, T arg1, Args... args){
    const char *name = strchr(names, ',');
    cerr.write(names, name-names) << " = " << arg1 << endl;
    _F(name+2, args...);
}
template<typename T1, typename T2> istream& operator>>(istream& in, pair<T1, T2> &q){
    in >> q.F >> q.S; return in;
}
template<typename T1, typename T2> ostream& operator<<(ostream& out, pair<T1, T2> &q){
    out << q.F << " " << q.S; return out;
}
template< typename T1, typename T2> pair<T1, T2> operator+(pair<T1, T2> p1, pair<T1, T2> p2){
    return {p1.F+p2.F, p1.S+p2.S};
}
template< typename T1, typename T2> pair<T1, T2> operator-(pair<T1, T2> p1, pair<T1, T2> p2){
    return {p1.F-p2.F, p1.S-p2.S};
}

void solve(){
    int s, w;
    cin >> s >> w;
    if(w >= s){
        cout << "unsafe" << endl;
    }else{
        cout << "safe" << endl;
    }
}

signed main(){

    ios_base::sync_with_stdio(0); 
    cin.tie(0); cout.tie(0);   

    int t = 1;
    start = clock(); 

    cout << fixed << setprecision(12);

    #ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin); 
    freopen("output.txt", "w", stdout);
    freopen("error.txt", "w", stderr);
    #endif

    //cin >> t;

    for(int i = 1; i <= t; ++i){
        //cout << "Case #" << i << ": "; 
        solve();
       // cout << endl;
    }
    //cerr << time(start);
    return 0;
}