1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
#include<cstdio>
#include<vector>
#include<algorithm>
#include<set>
#include<iostream>


using namespace std;

#define rep(i,n) for(int i=0; i<(int)n; i++)
#define st first
#define nd second
#define mp make_pair
#define pb push_back
#define mtup make_tuple

typedef vector<int> vi;
typedef pair<int,int> pi;
typedef vector<pi> vpii;
typedef set<int> SI;
typedef long long LL;
typedef tuple<int, int, int, int > cztINt;

#ifdef DEBUG
const bool debug = true;
#else
const bool debug = false;
#endif
int n,m,k,l;
const int inf = 1000 * 1000 * 1000 ;
const int MAKSN = 1000 * 100 + 13; // UZUPElnic
int x,y,x2,y2;

vector<tuple<int, int, int, int > > v, ans;

void readIn()
{
	l = scanf("%d",&n);
	rep(i,n)
	{
		l = scanf("%d %d %d %d",&x,&x2,&y,&y2);
		if(x > x2) swap(x, x2);
		if(y > y2) swap(y, y2);

		v.pb(mtup(x2,x,y2,y));
	}

	sort(v.begin(), v.end());
}

bool empty(int i)
{
	return get<0>(v[i]) == 0 && get<1>(v[i]) == 0 && get<2>(v[i]) == 0 && get<3>(v[i]) == 0;
}

void setEmpty(int i)
{
	v[i] = mtup(0,0,0,0);
}

bool intersects(int i, int j)
{
	int x12 = get<0>(v[i]);
	int x21 = get<1>(v[j]);
	int x11 = get<1>(v[i]);
	int x22 = get<0>(v[j]);

	int y12 = get<2>(v[i]);
	int y21 = get<3>(v[j]);
	int y11 = get<3>(v[i]);
	int y22 = get<2>(v[j]);


	return !(x12 <= x21 ||
		x22 <= x11 ||
		y12 <= y21 ||
		y22 <= y11);
}

void setInter(int i, int j)
{
	x = min(get<1>(v[i]), get<1>(v[j]));
	x2 = max(get<0>(v[i]), get<0>(v[j]));
	y = min(get<3>(v[i]), get<3>(v[j]));
	y2 = max(get<2>(v[i]), get<2>(v[j]));


	v[i] = (mtup(x2,x,y2,y));
}

void solve()
{
	bool found = true;

// 	int cnt = 0;
	while(found == true)
	{
// 		printf("TA\n");
		found = false;
		rep(i,v.size())
		{
			for(int j=i+1; j<(int)v.size(); j++)
			{
// 				printf("%d %d %d\n",i,j, intersects(i,j));
				if(i != j && !empty(i) && !empty(j) && intersects(i,j))
				{
					setInter(i,j);
					setEmpty(j);
// 					printf("%d \n",get<0>(v.back()));
					swap(v[j],v.back());
// 					printf("%d\n",get<0>(v.back()));
					v.pop_back();
					j--;
					found = true;
				}
			}
		}
	}

	rep(i,v.size())
	{
		if(!empty(i))
		{
			ans.pb(mtup(get<1>(v[i]), get<0>(v[i]), get<3>(v[i]), get<2>(v[i])));
		}
	}

	sort(ans.begin(), ans.end());

	printf("%d\n",ans.size());

	rep(i,ans.size())
	{
		printf("%d %d %d %d\n",get<0>(ans[i]), get<1>(ans[i]), get<2>(ans[i]), get<3>(ans[i]));
	}
}


int main()
{
	readIn();
	solve();
	return 0;
}