#include <cstdio>#include <cstdlib>#include <cstring>#include <vector>#include <cmath>#include <algorithm>using namespace std;#define maxn 20 const double EPS=1e-5;typedef struct vect{ int x,y; vect(int a=0, int b=0):x(a),y(b){} vect operator-(vect a) { return vect(x-a.x, y-a.y); } int operator/(vect a) { return x*a.y-y*a.x; } bool operator==(vect a) { return (x==a.x && y==a.y); }}vect;typedef struct dvect{ double x,y; bool operator==(dvect a) { return (fabs(x-a.x)<EPS && fabs(y-a.y)<EPS); }}dvect;typedef struct segment{ vect v1, v2; bool operator==(segment a) { return ((v1==a.v1&&v2==a.v2)||(v1==a.v2&&v2==a.v1)); }}segment;segment seg[maxn];bool check(int i){ for (int j=0; j<i; j++) if (seg[i]==seg[j]) return false; if (seg[i].v1.x==seg[i].v2.x && (seg[i].v1.x==0 || seg[i].v1.x==1000)) return false; if (seg[i].v1.y==seg[i].v2.y && (seg[i].v1.y==0 || seg[i].v1.y==1000)) return false; return true;}int min(int x, int y){if (x>y) return y; return x;}int max(int x, int y){if (x>y) return x; return y;}int multiply(vect p1, vect p2, vect p0){ int tmp=(p1-p0)/(p2-p0); return (tmp>0)?1:(tmp==0)?0:-1;}bool cross(segment seg1, segment seg2){ return( (max(seg1.v1.x,seg1.v2.x) >= min(seg2.v1.x,seg2.v2.x))&& (max(seg2.v1.x,seg2.v2.x) >=min(seg1.v1.x,seg1.v2.x))&& (max(seg1.v1.y,seg1.v2.y) >=min(seg2.v1.y,seg2.v2.y))&& (max(seg2.v1.y,seg2.v2.y) >=min(seg1.v1.y,seg1.v2.y)) && (multiply(seg1.v1, seg1.v2, seg2.v1)*multiply(seg1.v1, seg1.v2, seg2.v2)<0) && (multiply(seg2.v1, seg2.v2, seg1.v1)*multiply(seg2.v1, seg2.v2, seg1.v2)<0));}dvect crossvect(segment seg1, segment seg2){ vect p1=seg1.v1, p2=seg1.v2; vect q1=seg2.v1, q2=seg2.v2; dvect ret; double tmp1,tmp2; tmp1 = (q2.x-q1.x)*(p1.y-p2.y)-(p2.x-p1.x)*(q1.y-q2.y); tmp2 = (p1.y-q1.y)*(p2.x-p1.x)*(q2.x-q1.x) + q1.x*(q2.y-q1.y)*(p2.x-p1.x)-p1.x*(p2.y-p1.y)*(q2.x-q1.x); ret.x = tmp2/tmp1; tmp1 = (p1.x-p2.x)*(q2.y-q1.y)-(p2.y-p1.y)*(q1.x-q2.x); tmp2 = p2.y*(p1.x-p2.x)*(q2.y-q1.y) + (q2.x- p2.x)*(q2.y-q1.y)*(p1.y-p2.y)-q2.y*(q1.x-q2.x)*(p2.y-p1.y); ret.y = tmp2/tmp1; return ret; } int main(){ int n, ans, tmp, vnum; dvect cp; dvect v[maxn]; while (scanf("%d",&n)==1 && n) { ans=1; for (int i=0; i<n; i++) { scanf("%d%d%d%d", &seg[i].v1.x, &seg[i].v1.y, &seg[i].v2.x, &seg[i].v2.y); if (!check(i)) continue; tmp=0; vnum=0; for (int j=0, k; j<i; j++) if (cross(seg[i], seg[j])){ cp=crossvect(seg[i], seg[j]); for (k=0; k<vnum; k++) if (cp==v[k]) break; if (k==vnum) { tmp++; v[vnum++]=cp; } } ans+=tmp+1; } printf("%dn", ans); } return 0;}
