Why my code gets TLE again and again in SORT2D?

#include <bits/stdc++.h>

using namespace std;

bool compare(pair<int, int> a, pair<int, int> b){
return (a.first > b.first) || (a.first == b.first && a.second < b.second);
}

int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);

int t;
cin >> t;

while(t--){
    int n;
    cin >> n;

    vector<pair<int, int>> coordinates(n);

    for(int i=0; i<n; i++){
        cin >> coordinates[i].first >> coordinates[i].second;
    }

    sort(coordinates.begin(), coordinates.end(), compare);

    reverse(coordinates.begin(), coordinates.end());

    for(int i=0; i<n; i++){
        cout << coordinates[i].first << " " << coordinates[i].second << endl;
    }
}


return 0;

}