1 #include <cstdio>
 2 #include <iostream>
 3 #include <cstring>
 4
 5 using namespace std;
 6
 7 int n, lh, ll, cnt, sum;
 8 int next[62501], to[62501], head[251], g[251];
 9 bool vis[251];
10 struct node
11 {
12     int pos, minn, maxx;
13 }h[10001], l[10001];
14
15 void add(int x, int y)
16 {
17     to[cnt] = y;
18     next[cnt] = head[x];
19     head[x] = cnt++;
20 }
21
22 bool check(int i, int j)
23 {
24     if(h[i].pos < l[j].minn || h[i].pos > l[j].maxx) return 0;
25     if(l[j].pos < h[i].minn || l[j].pos > h[i].maxx) return 0;
26     return 1;
27 }
28
29 bool find(int u)
30 {
31     int i, v;
32     for(i = head[u]; i != -1; i = next[i])
33     {
34         v = to[i];
35         if(!vis[v])
36         {
37             vis[v] = 1;
38             if(!g[v] || find(g[v]))
39             {
40                 g[v] = u;
41                 return 1;
42             }
43         }
44     }
45     return 0;
46 }
47
48 int main()
49 {
50     int i, j, x1, y1, x2, y2;
51     scanf("%d", &n);
52     memset(head, -1, sizeof(head));
53     for(i = 1; i <= n; i++)
54     {
55         scanf("%d %d %d %d", &x1, &y1, &x2, &y2);
56         if(x1 == x2)
57         {
58             ++lh;
59             h[lh].pos = x1;
60             h[lh].minn = min(y1, y2);
61             h[lh].maxx = max(y1, y2);
62         }
63         else if(y1 == y2)
64         {
65             ++ll;
66             l[ll].pos = y1;
67             l[ll].minn = min(x1, x2);
68             l[ll].maxx = max(x1, x2);
69         }
70     }
71     for(i = 1; i <= lh; i++)
72      for(j = 1; j <= ll; j++)
73       if(check(i, j))
74        add(i, j);
75     for(i = 1; i <= lh; i++)
76     {
77         memset(vis, 0, sizeof(vis));
78         if(find(i)) sum++;
79     }
80     printf("%d", n - sum);
81     return 0;
82 }