#include <bits/stdc++.h>
using namespace std;
int m[1001][1001];
int main() {
  int x[3], y[3], i, j;
  for (i = 0; i < 3; i++) {
    cin >> x[i] >> y[i];
  }
  int a[3], b[3];
  for (i = 0; i < 3; i++) {
    a[i] = x[i];
    b[i] = y[i];
  }
  sort(x, x + 3);
  sort(y, y + 3);
  cout << y[2] - y[0] + x[2] - x[0] + 1 << endl;
  for (i = x[0]; i < x[2] + 1; i++) m[i][y[1]] = 1;
  for (i = min(y[1], b[1]); i < max(y[1], b[1]) + 1; i++) m[a[1]][i] = 1;
  for (i = min(y[1], b[2]); i < max(y[1], b[2]) + 1; i++) m[a[2]][i] = 1;
  for (i = min(y[1], b[0]); i < max(y[1], b[0]) + 1; i++) m[a[0]][i] = 1;
  for (i = 0; i < 1001; i++) {
    for (j = 0; j < 1001; j++) {
      if (m[i][j] == 1) cout << i << " " << j << endl;
    }
  }
}
