// Written By Mahtab Tanim
#include<bits/stdc++.h>
using namespace std;
#define MP ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define nl "\n"
#define End return 0
#define ll long long int
#define mp make_pair
#define pb push_back
#define ull unsigned long long int
#define pi acos(-1)
#define forn(i,a,b) for (int i=a;i<=b;i++)
int main()
{
    int s,w;
    cin>>s>>w;
    if(w>=s) cout<<"Unsafe"<<endl;
    else cout<<"Safe"<<nl;
End;
}
