#include <bits/stdc++.h>
using namespace std;
int main() {
// your code goes here
int t;
cin >> t;
while(t--){
int n;
cin >> n;
vector<pair<int,int>> vp;
for(int i=0;i<n;i++){
pair<int,int> p;
cin >> p.first >> p.second;
p.second *= -1;
vp.push_back(p);
}
sort(vp.begin(),vp.end());
for(int i=0;i<n;i++){
cout << vp[i].first << " "<< -1*vp[i].second<<endl;
}
}
return 0;
}
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