#include <bits/stdc++.h>
using namespace std;
const long long N = 1e6 + 5;
long long max(long long a, long long b) {
  if (a >= b)
    return a;
  else
    return b;
}
long long min(long long a, long long b) {
  if (a >= b)
    return b;
  else
    return a;
}
long long diff(long long a, long long b) {
  if (a >= b)
    return a - b;
  else
    return b - a;
}
void pairsort(long long a[], long long b[], long long n) {
  pair<long long, long long> pairt[n];
  for (long long i = 0; i < n; i++) {
    pairt[i].first = a[i];
    pairt[i].second = b[i];
  }
  sort(pairt, pairt + n);
  for (long long i = 0; i < n; i++) {
    a[i] = pairt[i].first;
    b[i] = pairt[i].second;
  }
}
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long rev(long long n) {
  long long ans = 0;
  while (n) {
    ans = ans * 10 + n % 10;
    n = n / 10;
  }
  return ans;
}
long long isPrime(long long n) {
  for (long long i = 2; i * i <= n; i++)
    if (n % i == 0) return 0;
  return 1;
}
long long C(long long n, long long r) {
  if (r > n - r) r = n - r;
  long long ans = 1;
  long long i;
  for (i = 1; i <= r; i++) {
    ans *= n - r + i;
    ans /= i;
  }
  return ans;
}
long long mod = 1e9 + 7;
long long modexpo(long long x, long long p) {
  long long res = 1;
  x = x % mod;
  while (p) {
    if (p % 2) {
      res = res * x;
    }
    p >>= 1;
    x = x * x % mod;
    res %= mod;
  }
  return res;
}
int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  long long x[3], y[3];
  for (long long i = 0; i < 3; i++) cin >> x[i] >> y[i];
  pairsort(x, y, 3);
  cout << x[2] - x[0] + max(max(y[0], y[1]), y[2]) -
              min(min(y[0], y[1]), y[2]) + 1
       << "\n";
  for (long long i = min(min(y[0], y[1]), y[2]);
       i <= max(max(y[0], y[1]), y[2]); i++)
    cout << x[1] << " " << i << "\n";
  for (long long i = x[0]; i < x[1]; i++) cout << i << " " << y[0] << "\n";
  for (long long i = x[2]; i > x[1]; i--) cout << i << " " << y[2] << "\n";
  return 0;
}
