#include <bits/stdc++.h>
using namespace std;
const int N = 1000005;
int x[5], y[5];
map<int, int> mp;
int main() {
  scanf("%d%d", &x[1], &y[1]), mp[x[1]] = y[1];
  scanf("%d%d", &x[2], &y[2]), mp[x[2]] = y[2];
  scanf("%d%d", &x[3], &y[3]), mp[x[3]] = y[3];
  std::sort(x + 1, x + 1 + 3), std::sort(y + 1, y + 1 + 3);
  printf("%d\n", x[3] - x[1] + y[3] - y[1] + 1);
  for (register int i = x[1]; i < x[2]; ++i) printf("%d %d\n", i, mp[x[1]]);
  for (register int i = x[3]; i > x[2]; --i) printf("%d %d\n", i, mp[x[3]]);
  for (register int i = y[1]; i <= y[3]; ++i) printf("%d %d\n", x[2], i);
  return 0;
}
