#include <bits/stdc++.h>
using namespace std;
long long MOD = 1000000007;
signed main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  pair<long long, long long> A[3];
  vector<long long> X;
  vector<long long> Y;
  for (long long i = 0; i < 3; i++) {
    cin >> A[i].first >> A[i].second;
    X.push_back(A[i].first);
    Y.push_back(A[i].second);
  }
  sort(X.begin(), X.end());
  sort(Y.begin(), Y.end());
  vector<pair<long long, long long> > res;
  for (long long i = 0; i < 3; i++) {
    long long x = X[1];
    long long y = Y[1];
    while (x != A[i].first || y != A[i].second) {
      if (x > A[i].first)
        x--;
      else if (x < A[i].first)
        x++;
      else if (y > A[i].second)
        y--;
      else if (y < A[i].second)
        y++;
      res.emplace_back(x, y);
    }
  }
  res.emplace_back(X[1], Y[1]);
  cout << res.size() << endl;
  for (long long i = 0; i < res.size(); i++) {
    cout << res[i].first << " " << res[i].second << endl;
  }
}
