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#include <cstdio>
#include <algorithm>
#include <unordered_map>
#include <vector>
#include <array>
using namespace std;

int base = 1;

class SegTree
{
    unordered_map<int, pair<int, int>> tree;
    
    int pa, pb, pk;
    SegTree *pc1, *pc2;
    
    int _insert(int v, int a, int b)
    {
	if(b <= pa || a >= pb) return tree.count(v) ? tree[v].first : 0;
	auto &tr = tree[v];
	tr.first = pk;
	if(a >= pa && b <= pb)
	    tr.second = pk;
	else
	{
	    tr.first = max(tr.first, tr.second);
	    tr.first = max(tr.first, _insert(v * 2, a, (a + b) / 2));
	    tr.first = max(tr.first, _insert(v * 2 + 1, (a + b) / 2, b));
	}
	return tr.first;
    }
    
    int _fix(int v, int a, int b)
    {
	if(b <= pa || a >= pb) return tree.count(v) ? tree[v].first : 0;
	auto &tr = tree[v], tr1 = pc1->tree.count(v) ? pc1->tree[v] : make_pair(0, 0),
	    tr2 = pc2->tree.count(v) ? pc2->tree[v] : make_pair(0, 0);
	if(tr1.first == 0 && tr2.first == 0) return tr.first;
	tr.first = max(tr.first, max(tr1.first, tr2.first));
	tr.second = max(tr.second, max(tr1.second, tr2.second));
	if(a < pa || b > pb)
	{
	    tr.first = max(tr.first, _fix(v * 2, a, (a + b) / 2));
	    tr.first = max(tr.first, _fix(v * 2 + 1, (a + b) / 2, b));
	}
	return tr.first;
    }
    
    int _findMax(int v, int a, int b)
    {
	if(b <= pa || a >= pb) return 0;
	auto tr = tree[v];
	if(a >= pa && b <= pb)
	    return tr.first;
	return max(tr.second, max(_findMax(v * 2, a, (a + b) / 2), _findMax(v * 2 + 1, (a + b) / 2, b)));
    }
    
public:
    void insert(int a, int b, int k)
    {
	pa = a; pb = b; pk = k;
	_insert(1, 0, base);
    }
    
    void fix(int a, int b, SegTree *child1, SegTree *child2)
    {
	pa = a; pb = b; pc1 = child1; pc2 = child2;
	_fix(1, 0, base);
    }
    
    int findMax(int a, int b)
    {
	pa = a; pb = b;
	return _findMax(1, 0, base);
    }
};

class SegTree2D
{
    vector<SegTree> tree1, tree2;
    
    int px1, px2, py1, py2, pk;

    void insert(int v, int a, int b)
    {
	if(b <= px1 || a >= px2) return;
	tree1[v].insert(py1, py2, pk);
	if(a >= px1 && b <= px2) tree2[v].insert(py1, py2, pk);
	else
	{
	    insert(v * 2, a, (a + b) / 2);
	    insert(v * 2 + 1, (a + b) / 2, b);
	    tree1[v].fix(py1, py2, &tree1[v * 2], &tree1[v * 2 + 1]);
	}
    }
    
    int findMax(int v, int a, int b)
    {
	if(b <= px1 || a >= px2) return 0;
	if(a >= px1 && b <= px2) return tree1[v].findMax(py1, py2);
	int ans = tree2[v].findMax(py1, py2);
	return max(ans, max(findMax(v * 2, a, (a + b) / 2), findMax(v * 2 + 1, (a + b) / 2, b)));
    }
    
public:
    SegTree2D() : tree1(base * 2), tree2(base * 2) { }
    
    void insert(int x1, int y1, int x2, int y2, int k)
    {
	px1 = x1; px2 = x2; py1 = y1; py2 = y2; pk = k;
	insert(1, 0, base);
    }
    
    int findMax(int x1, int y1, int x2, int y2)
    {
	px1 = x1; px2 = x2; py1 = y1; py2 = y2;
	return findMax(1, 0, base);
    }
};

const int N = 100001;
int X1[N], Y1[N], X2[N], Y2[N];

int main()
{
    int n;
    scanf("%d", &n);
    vector<int> xp, yp;
    for(int i = 1; i <= n; i++)
    {
	scanf("%d %d %d %d", X1 + i, X2 + i, Y1 + i, Y2 + i);
	xp.push_back(X1[i]);
	xp.push_back(X2[i]);
	yp.push_back(Y1[i]);
	yp.push_back(Y2[i]);
    }
    sort(xp.begin(), xp.end());
    sort(yp.begin(), yp.end());
    for(int i = 1; i <= n; i++)
    {
	X1[i] = lower_bound(xp.begin(), xp.end(), X1[i]) - xp.begin();
	X2[i] = lower_bound(xp.begin(), xp.end(), X2[i]) - xp.begin();
	Y1[i] = lower_bound(yp.begin(), yp.end(), Y1[i]) - yp.begin();
	Y2[i] = lower_bound(yp.begin(), yp.end(), Y2[i]) - yp.begin();
	while(base < X2[i] || base < Y2[i]) base *= 2;
    }
    SegTree2D tree;
    for(int i = 1; i <= n; i++)
    {
	while(true)
	{
	    int k = tree.findMax(X1[i], Y1[i], X2[i], Y2[i]);
	    if(k == 0) break;
	    X1[i] = min(X1[i], X1[k]);
	    Y1[i] = min(Y1[i], Y1[k]);
	    X2[i] = max(X2[i], X2[k]);
	    Y2[i] = max(Y2[i], Y2[k]);
	    tree.insert(X1[k], Y1[k], X2[k], Y2[k], 0);
	    X1[k] = -1;
	}
	tree.insert(X1[i], Y1[i], X2[i], Y2[i], i);
    }
    vector<int> ans;
    for(int i = 1; i <= n; i++)
	if(X1[i] != -1) ans.push_back(i);
    sort(ans.begin(), ans.end(), [](int a, int b)
	{
	    return make_tuple(X1[a], X2[a], Y1[a], Y2[a]) < make_tuple(X1[b], X2[b], Y1[b], Y2[b]);    
	});
    printf("%d\n", ans.size());
    for(auto x: ans)
	printf("%d %d %d %d\n", xp[X1[x]], xp[X2[x]], yp[Y1[x]], yp[Y2[x]]);
}