#include <bits/stdc++.h>
using namespace std;
int x[4];
int y[4];
int ii[4] = {1, -1, 0, 0};
int jj[4] = {0, 0, -1, 1};
int main() {
  ios_base::sync_with_stdio(0);
  int x1, x2, x3, y1, y2, y3;
  for (int i = 1; i <= 3; i++) {
    cin >> x[i] >> y[i];
  }
  set<pair<int, int>> s;
  long long xx = 0, yy = 0;
  long long d = 1e9;
  for (int j = 0; j <= 1000; j++) {
    for (int i = 0; i <= 1000; i++) {
      if (abs(x[1] - i) + abs(y[1] - j) + abs(x[2] - i) + abs(y[2] - j) +
              abs(x[3] - i) + abs(y[3] - j) <
          d) {
        xx = i;
        yy = j;
        d = abs(x[1] - i) + abs(y[1] - j) + abs(x[2] - i) + abs(y[2] - j) +
            abs(x[3] - i) + abs(y[3] - j);
      }
    }
  }
  for (int t = 1; t <= 3; t++) {
    int i, j;
    i = xx;
    j = yy;
    s.insert({x[t], y[t]});
    while (i != x[t] || j != y[t]) {
      s.insert({i, j});
      for (int e = 0; e < 4; e++) {
        if (abs(i - x[t]) > abs(i + ii[e] - x[t]) ||
            abs(j - y[t]) > abs(j + jj[e] - y[t])) {
          i += ii[e];
          j += jj[e];
          break;
        }
      }
    }
  }
  cout << s.size() << '\n';
  for (auto p : s) {
    cout << p.first << ' ' << p.second << '\n';
  }
}
