//nani?
#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp> // Common file
#include <ext/pb_ds/tree_policy.hpp> // Including tree_order_statistics_node_update
#include <ext/pb_ds/detail/standard_policies.hpp>
#define pi acos(-1);
#define fs first
#define sc second
#define pb push_back
#define mp make_pair
#define f(i,a,b) for( int i = a; i < b ; i++ )
#define sor(a) sort( a.begin(), a.end() )
#define rsor(a) sort( a.rbegin(), a.rend() )
#define fastio ios_base::sync_with_stdio(0);cin.tie(0)
//#define inf 1LL<<62
typedef long long ll;
typedef double ld;
using namespace std;
using namespace __gnu_pbds;
const int inf=1e7;
const ll MOD=1e9+7;
const ll mod=998244353;
// ac cmtr;
const int MAX_N = 2e5+5;
typedef tree<int,null_type,less<int>,rb_tree_tag,tree_order_statistics_node_update>ordered_set;

#define TRACE
#ifdef TRACE
#define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1>
void __f(const char* name, Arg1&& arg1) {
  cout << name << " : " << arg1 << endl;}
 
template <typename Arg1, typename... Args>
void __f(const char* names, Arg1&& arg1, Args&&... args) {
  const char* comma = strchr(names + 1, ',');
  cout.write(names, comma - names) << " : " << arg1<<" | ";
  __f(comma+1, args...);}
#else
#define trace(...)
#endif
//---------------------------

ll a[MAX_N];
ll b[MAX_N];
ll cnt[MAX_N][4];

int main(){
    fastio;
    ll n,m;
  	cin>>n>>m;
  	if(n>m) cout<<"safe"<<endl;
  	else cout<<"unsafe"<<endl;

    
} 