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#include <cstdio>
#include <iostream>
#include <vector>
#include <algorithm>
#include <string>

using namespace std;

struct terytorium {
  int x1, x2, y1, y2;
};

bool xComparator(const terytorium& lhs, const terytorium& rhs) {
  return lhs.x1 < rhs.x1;
}

bool yComparator(const terytorium& lhs, const terytorium& rhs) {
  return lhs.y1 < rhs.y1;
}

bool xxyyComparator(const terytorium& lhs, const terytorium& rhs) {
  if (lhs.x1 < rhs.x1)
    return true;
  else if (lhs.x1 > rhs.x1)
    return false;

  if (lhs.x2 < rhs.x2)
    return true;
  else if (lhs.x2 > rhs.x2)
    return false;
    
  if (lhs.y1 < rhs.y1)
    return true;
  else if (lhs.y1 > lhs.y1)
    return false;

  if (lhs.y2 < rhs.y2)
    return true;
  return false;
}

inline bool intercepts(const terytorium& a, const terytorium& b) {
  return a.x1 < b.x2 && a.x2 > b.x1 && a.y1 < b.y2 && a.y2 > b.y1;
}

inline terytorium merge(const terytorium& a, const terytorium& b) {
  terytorium t = {min(a.x1, b.x1), max(a.x2, b.x2), min(a.y1, b.y1), max(a.y2, b.y2)};
  return t;
}


int main() {
  int n;
  scanf("%d", &n);
  vector<terytorium> ter(n);
  for (int i = 0; i < n; ++i) {
    int x1, x2, y1, y2;
    scanf("%d%d%d%d", &x1, &x2, &y1, &y2);
    terytorium t = {x1, x2, y1, y2};
    ter[i] = t;
  }

  sort(ter.begin(), ter.end(), xxyyComparator);

  int k = 0;

  while(true) {
    /*
    printf("tersize: %lld, k=%d\n", ter.size(),k);
    for (int i = 0; i < ter.size(); ++i) {
      printf("%d %d %d %d\n", ter[i].x1, ter[i].x2, ter[i].y1, ter[i].y2);
    }
    printf("\n");
    */

    if (k+1 >= ter.size()) break;
    bool clearRun = true;
    terytorium newTerytory = ter[k];
    int eee = k+1;

    while (eee < ter.size() && newTerytory.x2 > ter[eee].x1) eee++;

    vector<int> tersToRem;
    tersToRem.push_back(k);

    for (int i = k+1; i < eee; ++i) {
      if (intercepts(newTerytory, ter[i])) {
        clearRun = false;
        newTerytory = merge(newTerytory, ter[i]);
        tersToRem.push_back(i);
      }
    }

    if (tersToRem.size() > 1) {
      /*
      printf("Ters to rem: ");
      for (int i = 0; i < tersToRem.size(); ++i)
        printf("%d ", tersToRem[i]);
      printf("\n");
      */

      for (int i = tersToRem.size()-1; i >= 0; --i) {
        ter.erase(ter.begin()+tersToRem[i]);
      }

      ter.insert(ter.begin()+k, newTerytory);
      //ter.push_back(newTerytory);
      //sort(ter.begin(), ter.end(), xComparator);
    }

    if (clearRun) {
      k++;
    } else {
      k = 0;
    }
  }


  sort(ter.begin(), ter.end(), xxyyComparator);
  printf("%lu\n", ter.size());
  for (int i = 0; i < ter.size(); ++i) {
    printf("%d %d %d %d\n", ter[i].x1, ter[i].x2, ter[i].y1, ter[i].y2);
  }

}