1 //0MS    240K    1146 B    C++
 2 #include<stdio.h> 
 3 #include<math.h>
 4 struct node{
 5     double x1,y1;
 6     double x2,y2;        
 7 }p[105];
 8 double Max(double a,double b)
 9 {
10     return a>b?a:b;
11 }
12 double Min(double a,double b)
13 {
14     return a<b?a:b;
15 }
16 int judge_in(node a,double x,double y)
17 {
18     if(x>=Min(a.x1,a.x2)&&x<=Max(a.x1,a.x2)&&y>=Min(a.y1,a.y2)&&y<=Max(a.y1,a.y2))
19         return 1;
20     return 0;
21 }
22 int judge(node a,node b)
23 {
24     double k1,k2,b1,b2;
25     if(a.x1==a.x2) k1=0;
26     else k1=(a.y2-a.y1)/(a.x2-a.x1);
27     if(b.x1==b.x2) k2=0;
28     else k2=(b.y2-b.y1)/(b.x2-b.x1);
29     if(k1==k2) return 0;
30     
31     b1=a.y1-k1*a.x1;
32     b2=b.y1-k2*b.x1;
33     
34     double x,y;
35     x=(b2-b1)/(k1-k2);
36     y=k1*x+b1;
37     
38     if(judge_in(a,x,y) && judge_in(b,x,y))  return 1;
39     return 0; 
40 }
41 int main(void)
42 {
43     int n;
44     while(scanf("%d",&n)!=EOF && n)
45     {
46         for(int i=0;i<n;i++)
47             scanf("%lf%lf%lf%lf",&p[i].x1,&p[i].y1,&p[i].x2,&p[i].y2);
48         int cnt=0;
49         for(int i=0;i<n;i++)
50             for(int j=i+1;j<n;j++)
51                 cnt+=judge(p[i],p[j]);
52         printf("%d\n",cnt);
53     }
54     return 0;
55 }