#include <bits/stdc++.h>
using namespace std;
#define endl "\n"
#define IOS ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define int long long
#define pb push_back
#define mp make_pair
#define ff first
#define ss second
#define BS binary_search
#define all(c) (c).begin(),(c).end()
#define sz(x) (int)(x).size()
#define get(a,t) get<a>(t)
#define EPS 0.000000001 //1e-9
using pii=pair<int,int>;
const int INF=1e18;

void dprint(string s) { cout << endl;}
void dprint() { cout << endl;}
template <class T, class... U> void dprint(string s, T t, U... u) 
{int w=s.find(','); cout <<"["<< s.substr(0,w) << ": " << t << "] " ; dprint(s.substr(w+1, sz(s)-w), u...);} 


#define DEBUG 
#ifdef DEBUG
#define dbg(X...) dprint(#X,X)
#else
#define dbg(X...); 
#endif
const int N=100005;

int32_t main()
{
	IOS;
	int s,w; cin>>s>>w;
	if(w>=s)
		cout<<"Unsafe";
	else 
		cout<<"Safe";
	return 0;
}