main.cpp

#include <algorithm>
#include <iostream>
#include <vector>
using namespace std;

void solve() {
   int n;
   cin >> n;
   vector<pair<int, int>> arr(n);
   for (int i = 0; i < n; i++) cin >> arr[i].first >> arr[i].second;

   sort(arr.begin(), arr.end(), [&](auto &a, auto &b) {
      if (a.second != b.second) return a.second < b.second;
      return a.first < b.first;
   });
   for (int i = 0; i < n; i++) cout << arr[i].first << ' ' << arr[i].second << '\n';
}

signed main() {
   solve();
   return 0;
}