#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>
#include <set>
#include <array>
using namespace std;

int main() {

    set<pair<int, int> > st;
    st.insert({1, 2});

    for(auto x : st) {
        cout << x.first << " " << x.second << endl;
    }

    return 0;
}