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#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <list>
#include <queue>
#include <set>
#include <map>
#include <numeric>
#include <utility>
#include <string>
#include <sstream>
#include <algorithm>
#include <tuple>

using namespace std;
const int N = 100002;

namespace pie {

const int TR = 1;
int x1[N], x2[N], y1[N], y2[N];
int x[2*N], y[2*N];
bool removed[N];
bool changed[N];
const int INF = 0x7fffffff;

typedef tuple<int,int,int,int> t4;
typedef tuple<bool,int,int,int,int> t5;

bool overlaps(int a, int b) {
  if (x2[b] <= x1[a]) return false;
  if (x1[b] >= x2[a]) return false;
  if (y2[b] <= y1[a]) return false;
  if (y1[b] >= y2[a]) return false;
  return true;
}

t5 join(const t5 &a, const t5 &b) {
  if (!get<0>(a)) return b;
  if (!get<0>(b)) return a;
  return make_tuple(
      true,
      min(get<1>(a), get<1>(b)),
      max(get<2>(a), get<2>(b)),
      min(get<3>(a), get<3>(b)),
      max(get<4>(a), get<4>(b))
      );
}

t5 join(int a, int b) {
  x1[a] = min(x1[a], x1[b]);
  x2[a] = max(x2[a], x2[b]);
  y1[a] = min(y1[a], y1[b]);
  y2[a] = max(y2[a], y2[b]);
//  printf("join(%d, %d)[%d %d][%d %d]\n", a, b, x1[a]/2, y1[a]/2, x2[a]/2, y2[a]/2);
  removed[b] = true;
  changed[a] = true;
  return make_tuple(true, x1[a], x2[a], y1[a], y2[a]);
}

bool checkChanged(const vector<int> &in) {
  for (int i : in) {
    if (changed[i]) return true;
  }
  return false;
}

void clearChanged(const vector<int> &in) {
  for (int i : in) {
    changed[i] = false;
  }
}

t5 split(const vector<int> &in, vector<int> &r1, vector<int> &r2, vector<int> &r3, vector<int> &r4, t5 tx) {
  t5 ret (false, 0, 0, 0, 0);
  int n = in.size();
  for (int i = 0; i < n; ++i) {
    const int j = in[i];
    x[2 * i]     = x1[j];
    x[2 * i + 1] = x2[j];
    y[2 * i]     = y1[j];
    y[2 * i + 1] = y2[j];
  }

  nth_element(x, x + n + n, x + n);
  int xm = x[n] - 1;
  nth_element(y, y + n + n, y + n);
  int ym = y[n] - 1;

  int mid = -1;
  for (int i = 0; i < n; ++i) {
    const int j = in[i];
    if (removed[j]) continue;
    if (x1[j] < xm && x2[j] > xm && y1[j] < ym && y2[j] > ym) {
      if (mid >= 0) {
        auto rt5 = join(mid, j);
        ret = join(ret, rt5);
        tx = join(tx, rt5);
        continue;
      } else {
        mid = j;
      }
    }
    if (x1[j] < xm && y1[j] < ym) {
      r1.push_back(j);
    }
    if (x1[j] < xm && y2[j] > ym) {
      r2.push_back(j);
    }
    if (x2[j] > xm && y1[j] < ym) {
      r3.push_back(j);
    }
    if (x2[j] > xm && y2[j] > ym) {
      r4.push_back(j);
    }
  }
  if (get<0>(tx)) {
    if (xm <= get<1>(tx)) {
      r1.clear();
      r2.clear();
    }
    if (xm >= get<2>(tx)) {
      r3.clear();
      r4.clear();
    }
    if (ym <= get<3>(tx)) {
      r1.clear();
      r3.clear();
    }
    if (ym >= get<4>(tx)) {
      r2.clear();
      r3.clear();
    }
  }
  /*
  if (!checkChanged(r1)) r1.clear();
  if (!checkChanged(r2)) r2.clear();
  if (!checkChanged(r3)) r3.clear();
  if (!checkChanged(r4)) r4.clear();
  */
  return ret;
}

t5 checkAll(const vector<int> &in) {
  t5 ret (false, 0, 0, 0, 0);
  const int n = in.size();
  for (int i = 0; i < n; ++i) {
    if (removed[in[i]]) continue;
    for (int j = i + 1; j < n; ++j) {
      if (removed[in[j]]) continue;
      if (overlaps(in[i], in[j])) {
        auto rtx = join(in[i], in[j]);
        ret = join(ret, rtx);
        i = -1;
        break;
      }
    }
  }
  return ret;
}

t5 go(const vector<int> &in) {
 // printf("go(%d)\n", (int)in.size());
  const int n = in.size();
  if (n < TR) {
    return checkAll(in);
  }
  t5 ret (false, 0, 0, 0, 0);
  t5 r(true, -INF, INF, -INF, INF);
  do {
    vector<int> v1, v2, v3, v4;
    r = split(in, v1, v2, v3, v4, r);
    size_t vs = max(max(v1.size(), v2.size()), max(v3.size(), v4.size()));
    if (vs == in.size()) {
      return join(join(ret, r), checkAll(in));
    }
 
    r = join(r, go(v1));
    r = join(r, go(v2));
    r = join(r, go(v3));
    r = join(r, go(v4));
    ret = join(r, ret);
  } while (get<0>(r));
  return ret;
}

int main() {
  int n;
  scanf("%d", &n);
  vector<int> v(n);
  for (int i = 0; i < n; ++i) {
    scanf("%d%d%d%d", x1 + i, x2 + i, y1 + i, y2 + i);
    x1[i] *= 2;
    x2[i] *= 2;
    y1[i] *= 2;
    y2[i] *= 2;
    removed[i] = false;
    changed[i] = true;
    v[i] = i;
  }
  go(v);
  vector<t4> ret;
  for (int i = 0; i < n; ++i) {
    if (removed[i]) continue;
    ret.push_back(make_tuple(x1[i]/2, x2[i]/2, y1[i]/2, y2[i]/2));
  }
  sort(ret.begin(), ret.end());
  printf("%d\n", (int)ret.size());
  for (size_t i = 0; i < ret.size(); ++i) {
    printf("%d %d %d %d\n", get<0>(ret[i]), get<1>(ret[i]), get<2>(ret[i]), get<3>(ret[i]));
  }
  return 0;
}

} // namespace pie

int main() {
  return pie::main();
}