#include <bits/stdc++.h>   using namespace std;   int main() {     pair<int, int> orig[3];     int a, b, x1, y1, t = 0;     for (int i = 0; i < 3; i++) {       cin >> orig[i].first >> orig[i].second;     }     cout <<  3  << endl;     a = (orig[0].first + orig[1].first) / 2;     b = (orig[0].second + orig[1].second) / 2;     cout << (orig[0].first + orig[1].first - orig[2].first) <<              << (orig[0].second + orig[1].second - orig[2].second) << endl;     a = (orig[1].first + orig[2].first);     b = (orig[1].second + orig[2].second);     cout << (a - orig[0].first) <<     << (b - orig[0].second) << endl;     a = (orig[0].first + orig[2].first);     b = (orig[0].second + orig[2].second);     cout << (a - orig[1].first) <<     << (b - orig[1].second) << endl;   }   