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#include <cstdio>
#include <cstdlib>
#include <list>
#include <algorithm>

using namespace std;

typedef pair< pair<int, int>, pair<int, int> > prostokat;

bool intersect(prostokat &a, prostokat &b) {
    return (a.first.first < b.first.second && a.first.second > b.first.first &&
        a.second.first < b.second.second && a.second.second > b.second.first);
}

int min(int a, int b) {
    return a > b ? b : a;
}

int max(int a, int b) {
    return a > b ? a : b;
}

int main() {
    int n;
    scanf("%d\n", &n);
    list< prostokat > l;
    for (int i = 0; i < n; ++i) {
        int a, b, c, d;
        scanf("%d %d %d %d\n", &a, &b, &c, &d);
        l.push_back(make_pair(make_pair(a, b), make_pair(c, d)));        
    }
    list<prostokat>::iterator i, j;
    bool stop;
    do {
    stop = true;
    for (i = l.begin(); i != l.end(); ++i) {
        j = i;
        j++;
        for (; j != l.end(); ++j) {
            if (intersect(*i, *j)) {
                (*i) = make_pair(
                            make_pair(
                                min(i->first.first, j->first.first), 
                                max(i->first.second, j->first.second)), 
                            make_pair(
                                min(i->second.first, j->second.first), 
                                max(i->second.second, j->second.second))
                        );
                stop = false;
                l.erase(j);
                break;
            }
        }
    }
    } while (!stop);
    l.sort();
    printf("%d\n", (int) l.size());
    for (i = l.begin(); i != l.end(); ++i) {
        printf("%d %d %d %d\n", i->first.first, i->first.second, i->second.first, i->second.second);
    }
    return 0;
}