func_code_string: #include <bits/stdc++.h>   using namespace std;   pair<int, int> a[100 * 100 + 5];   pair<int, int> as[100 * 10000 + 5];   pair<int, int> ass[100 * 1000 * 7 + 5];   int p = 0;   int badbakhti(int l, int r) {     if (r - l < 2) {       return 1;     }     int h = -10000 * 100000, e = (r + l) / 2;     h = a[e].first;     for (int i = l; i < r; i++) {       if (i != e) {         as[p].first = a[e].first;         as[p].second = a[i].second;         p++;       }     }     badbakhti(l, e);     badbakhti(e, r);     return 1;   }   int main() {     int n;     cin >> n;     int d, q;     for (int i = 0; i < n; i++) {       cin >> d >> q;       a[i] = make_pair(d, q);       as[p] = make_pair(d, q);       p++;     }     sort(a, a + n);     badbakhti(0, n);     sort(as, as + p);     int u = 0, er = 0;     for (int i = 0; i < p; i++) {       u = i;       while (as[i].first == as[u].first && as[i].second == as[u].second) u++;       ass[er].first = as[i].first;       ass[er].second = as[i].second;       er++;       i = u - 1;     }     cout << er << endl;     for (int i = 0; i < er; i++) {       cout << ass[i].first <<     << ass[i].second << endl;     }   }   