#include <bits/stdc++.h>
#define mp make_pair
#define eb emplace_back
#define fi first
#define se second
#define bit(n) 1 << n
using namespace std;
using cd = complex <double>;

typedef pair <int, int> pii;
typedef vector <int> vi;
typedef vector <pair <int, int> > vii;
typedef map <int, int> mii;

const int Inf = 1000000007;
const int mod = 1000000007;
const double Pi = acos(-1);

void Fastio()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
}

int s, w;

void Solve()
{	
	cin >> s >> w;
	if(s <= w)
	{
		cout << "unsafe";
	}	
	else
	{
		cout << "save";
	}
}

int main()
{
//	freopen("PARK.inp", "r", stdin);
//	freopen("PARK.out", "w", stdout);
	Fastio();
	Solve();
}