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//Tadrion
#include <cstdio>
#include <vector>
#include <iostream>
#include <deque>
#include <map>
#include <set>
#include <string>
#include <cstring>
#include <cstdlib>
#include <cmath>
#include <queue>
#include <stack>
#include <algorithm>
#include <utility>
using namespace std;
#define MAX(a,b) ((a) > (b) ? (a) : (b))
#define MIN(a,b) ((a) < (b) ? (a) : (b))
#define CLEAR(x) (memset(x,0,sizeof(x)))
#define SZ(x) ((int)(x).size())
#define ALL(x) (x).begin(),(x).end()
#define VAR(v, n) __typeof(n) v = (n)
#define FOR(x, b, e) for(int x = b; x <= (e); ++x)
#define FORD(x, b, e) for(int x = b; x >= (e); --x)
#define REP(x, n) for(int x = 0; x < (n); ++x)
#define FOREACH(i, c) for(VAR(i,(c).begin()); i != (c).end(); ++i)
#define DBG(v) cout<<#v<<" = "<<v<<endl;
#define IN(x,y) ((y).find(x)!=(y).end())
#define ST first
#define ND second
#define PB push_back
#define PF push_front
#define MP make_pair
typedef long long int LL;
typedef pair<int,int> PII;
typedef vector<int> VI;

int n;

void do1() {
    vector<pair<PII,PII> > v,v2;
    vector<pair<PII,PII> > res;
    int a,b,c,d;
    FOR(i,1,n) {
        scanf("%d %d %d %d",&a,&b,&c,&d);
        v.PB(MP(MP(a,c),MP(b,d)));
    }
    int zm = 1;
    while(zm) {
            zm=0;
    REP(i,SZ(v)) for(int j = i+1; j < SZ(v); j++) {
        if(v[i].ST.ST <= v[j].ST.ST &&
           v[i].ST.ND <= v[j].ST.ND &&
           v[i].ND.ST >= v[j].ST.ST &&
           v[i].ND.ND >= v[j].ST.ND) {
            pair<PII,PII> p = MP(MP(v[i].ST.ST,v[i].ST.ND),MP(MAX(v[i].ND.ST,v[j].ND.ST),MAX(v[i].ND.ND,v[j].ND.ND)));
            v[i] = p;
            v[j] = v.back();
            v.pop_back();
            zm=1;
            j--;
           }
    }
    }
    REP(i,SZ(v)) res.PB(MP(MP(v[i].ST.ST,v[i].ND.ST),MP(v[i].ST.ND,v[i].ND.ND)));
    sort(res.begin(),res.end());
    printf("%d\n",SZ(res));
    REP(i,SZ(res)) printf("%d %d %d %d\n",res[i].ST.ST,res[i].ST.ND,res[i].ND.ST,res[i].ND.ND);
}

void do2() {

}

int main() {
  scanf("%d",&n);
  if(n <= 100000) do1();
  else do2();
  return 0;
}