#include<cstdio>

 #include<cstring>

 #include<iostream>

 #include<algorithm>

 #include<cmath>

 #define inf 1e10

 #define maxn 10010

 using namespace std;

 int n,head,tail,tot,cnt;

 double ans;

 const double eps=1e-;

 struct point{double x,y;}p[maxn];

 point operator +(point x,point y){return (point){x.x+y.x,x.y+y.y};}

 point operator -(point x,point y){return (point){x.x-y.x,x.y-y.y};}

 struct line{double ang,a,b,c;point pt;}li[maxn],que[maxn];

 double dot(point a,point b){return a.x*b.x+a.y*b.y;}

 double cross(point x,point y,point z){return (x.x-z.x)*(y.y-z.y)-(x.y-z.y)*(y.x-z.x);}

 bool includ(line x,point y){return y.x*x.a+y.y*x.b+x.c<=eps;}

 bool comp(line x,line y){

     if(x.ang==y.ang)return includ(y,x.pt);

     return x.ang<y.ang;

 }

 point calc(line s1,line s2){

     double v1=s1.b*s2.c-s1.c*s2.b,v2=s1.c*s2.a-s1.a*s2.c;

     double v0=s1.a*s2.b-s1.b*s2.a;

     return (point){v1/v0,v2/v0};

 }

 bool check(line x,line y,line z){return !includ(z,calc(x,y));}

 bool solve(){

     head=;tail=;

     for(int i=;i<=tot;i++){

         if(i>&&fabs(li[i].ang-li[i-].ang)<=eps)continue;

         while(head<tail&&check(que[tail-],que[tail],li[i]))tail--;

         while(head<tail&&check(que[head],que[head+],li[i]))head++;

         que[++tail]=li[i];

     }

     while(head<tail&&check(que[tail-],que[tail],que[head]))tail--;

     while(head<tail&&check(que[head],que[head+],que[tail]))head++;

     for(int i=head;i<tail;i++)p[++cnt]=calc(que[i],que[i+]);

     p[++cnt]=calc(que[head],que[tail]);

     p[cnt+]=p[];

 }

 void getans(){

     ans=;for(int i=;i<=cnt;i++)ans+=cross(p[i],p[i+],(point){,});ans=fabs(ans)/;

 }

 int main(){

     //freopen("polygon.in","r",stdin);

     //freopen("polygon.out","w",stdout);

     scanf("%d",&n);

     for(int i=;i<=n;i++){

         double x,y,z;

         scanf("%lf%lf%lf",&x,&y,&z);

         li[++tot].a=x;li[tot].b=y;li[tot].c=z;

     }

     ++tot,li[tot].a=-,li[tot].b=,li[tot].c=-inf;

     ++tot,li[tot].a=,li[tot].b=,li[tot].c=-inf;

     ++tot,li[tot].a=,li[tot].b=-,li[tot].c=-inf;

     ++tot,li[tot].a=,li[tot].b=,li[tot].c=-inf;

     for(int i=;i<=tot;i++){

         li[i].ang=atan2(li[i].b,li[i].a);

         if(li[i].b) li[i].pt=(point){,-li[i].c/li[i].b};

         else li[i].pt=(point){-li[i].c/li[i].a,};

     }

     sort(li+,li+tot+,comp);

     solve();getans();

     printf("%.0lf\n",ans);

     return ;

 }