#include<bits/stdc++.h>
#include<ext/pb_ds/assoc_container.hpp>
#include<ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
template <typename T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
using namespace std;
#define a_macro(args...) sum(args)
#define mp make_pair
#define eb emplace_back
#define mt make_tuple
#define fi first
#define se second
#define pb push_back
#define rep(i, begin, end) for (__typeof(end) i = (begin) - ((begin) > (end)); i != (end) - ((begin) > (end)); i += 1 - 2 * ((begin) > (end)))

typedef long long ll;
const ll mod = 1e9+7;

typedef tuple<int,int,int> State; // operator< defined
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<pii> vpi;
typedef vector<ll> vll;
typedef pair<ll, ll> pll;
typedef double ld;

/*---------------Matrix Multiplication-------------------
struct matrix {
  // N is the size of the matrix
  int m[N][N];
  matrix()
  {
     memset(m,0,sizeof(m));
  }
  matrix operator * (matrix b)
  {
     matrix c = matrix();
     for (int i = 0; i < N; ++i)
       for (int j = 0; j < N; ++j)
         for (int k = 0; k < N; ++k) 
           c.m[i][j] = (c.m[i][j] + 1LL * m[i][k] * b.m[k][j]) % M;
     return c;
  }
};
// Note that this multiplication method can be used to multiplying numbers,matrixes,etc....
matrix modPow(matrix m,int n)
{
  if ( n == 0 )
    return unit; // the unit matrix - that is 1 for principal diagonal , otherwise 0
  matrix half = modPow(m,n/2);
  matrix out = half * half;
  if ( n % 2 )
    out = out * m;
  return out; 
}
-----------------END-----------------------------------*/
int sum() { return 0; }

template<typename T, typename... Args>
auto sum(T a, Args... args) { return a + sum(args...); }
template<class T> bool uin(T &a,T b) {return a > b ? (a == b, true) : false; }
template<class T> bool uax(T &a,T b) {return a < b ? (a == b, true) : false; }

int main(int argc, const char** argv) {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.precision(10);
    cout << fixed;
#ifndef ONLINE_JUDGE
	freopen("input.txt","r",stdin);
	freopen("output.txt","w",stdout);
	freopen("error.txt","w",stderr);
#endif

	int t,n,i,s;
	cin>>t;
	while(t--) {
	    cin>>n>>s;
	    if(n>=s)
        cout<<"unsafe\n";
      else
        cout<<"safe\n";
	}



    
#ifndef LOCAL_DEFINE
    cerr << "Time elapsed: "<< 1e1 * clock() / CLOCKS_PER_SEC << " s.\n";
#endif // LOCAL_DEFINE
    return 0;
}