#include <bits/stdc++.h>
using namespace std;
long long power(long long x, long long y);
long long mpower(long long x, long long y, long long p);
long long modInv(long long a, long long m);
long long gcdExtended(long long a, long long b, long long *x, long long *y);
bool isPrime(long long n);
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  long long t, i, j, k, l, p, q, r, x, y, z, a, b, c, d, f, n, m,
      M = 1000000007;
  long long x1, x2, x3, y1, y2, y3;
  string s;
  vector<pair<long long, long long> > v, w;
  vector<long long>::iterator itrv;
  unordered_map<long long, long long> N;
  set<long long> S;
  set<long long>::iterator itr;
  cin >> x1 >> y1 >> x2 >> y2 >> x3 >> y3;
  v.push_back({x1, y1});
  v.push_back({x2, y2});
  v.push_back({x3, y3});
  sort(v.begin(), v.end());
  x1 = v[0].first;
  x2 = v[1].first;
  x3 = v[2].first;
  y1 = v[0].second;
  y2 = v[1].second;
  y3 = v[2].second;
  c = 1;
  w.push_back({x1, y1});
  i = x1;
  j = y1;
  while (i < x2) {
    i++;
    c++;
    w.push_back({i, j});
  }
  if (y2 >= y1) {
    while (j < y2) {
      j++;
      c++;
      w.push_back({i, j});
    }
  } else {
    while (j > y2) {
      j--;
      c++;
      w.push_back({i, j});
    }
  }
  a = y1;
  b = y2;
  if (a > b) {
    swap(a, b);
  }
  if (y3 > b) {
    i = x2;
    j = b;
    while (i < x3) {
      i++;
      c++;
      w.push_back({i, j});
    }
    while (j < y3) {
      j++;
      c++;
      w.push_back({i, j});
    }
  } else if (y3 < a) {
    i = x2;
    j = a;
    while (i < x3) {
      i++;
      c++;
      w.push_back({i, j});
    }
    while (j > y3) {
      j--;
      c++;
      w.push_back({i, j});
    }
  } else {
    i = x2;
    j = y3;
    while (i < x3) {
      i++;
      c++;
      w.push_back({i, j});
    }
  }
  cout << c << "\n";
  for (i = 0; i < w.size(); i++) {
    cout << w[i].first << " " << w[i].second << "\n";
  }
  return 0;
}
long long modInv(long long a, long long m) {
  long long x, y;
  long long g = gcdExtended(a, m, &x, &y);
  long long res = (x % m + m) % m;
  return res;
}
long long gcdExtended(long long a, long long b, long long *x, long long *y) {
  if (a == 0) {
    *x = 0, *y = 1;
    return b;
  }
  long long x1, y1;
  long long gcd = gcdExtended(b % a, a, &x1, &y1);
  *x = y1 - (b / a) * x1;
  *y = x1;
  return gcd;
}
long long mpower(long long x, long long y, long long p) {
  long long res = 1;
  x = x % p;
  while (y > 0) {
    if (y & 1) res = (res * x) % p;
    y = y >> 1;
    x = (x * x) % p;
  }
  return res;
}
long long power(long long x, long long y) {
  long long res = 1;
  while (y > 0) {
    if (y & 1) res = res * x;
    y = y >> 1;
    x = x * x;
  }
  return res;
}
bool isPrime(long long n) {
  if (n <= 1) return false;
  if (n <= 3) return true;
  if (n % 2 == 0 || n % 3 == 0) return false;
  long long p = sqrt(n);
  for (int i = 5; i <= p; i = i + 6)
    if (n % i == 0 || n % (i + 2) == 0) return false;
  return true;
}
