#include <cstdio>

 #include <cstring>

 #include <algorithm>

 #include <cmath>

 #define maxn 1000000

 using namespace std;

 const double eps=(1e-);

 struct point

 {

     double x,y;

 };

 double a,b,c;

 int n,cutt=,m;

 point p1[maxn];

 point p2[maxn];

 point p3[maxn];

 void get(point c1,point c2)

 {

     a=c2.y-c1.y;

     b=c1.x-c2.x;

     c=c1.y*c2.x-c1.x*c2.y;

 }

 point insertsect(point c1,point c2)

 {

     double u=fabs(a*c1.x+b*c1.y+c);

     double v=fabs(a*c2.x+b*c2.y+c);

     point p;

     p.x=(c1.x*v+c2.x*u)/(u+v);

     p.y=(c1.y*v+c2.y*u)/(u+v);

     return p;

 }

 void cut()

 {

     int cutnum=;

     for(int i=; i<=m; i++)

     {

         if(a*p3[i].x+b*p3[i].y+c>=)

             p2[++cutnum]=p3[i];

         else

         {

             if(a*p3[i-].x+b*p3[i-].y+c>)

                 p2[++cutnum]=insertsect(p3[i-],p3[i]);

             if(a*p3[i+].x+b*p3[i+].y+c>)

                 p2[++cutnum]=insertsect(p3[i+],p3[i]);

         }

     }

     for(int i=; i<=cutnum; i++)

         p3[i]=p2[i];

     p3[cutnum+]=p2[]; p3[]=p2[cutnum];

     m=cutnum;

 }

 int main()

 {

     while(scanf("%d",&n)!=EOF)

     {

         if(n==) break;

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

         {

             scanf("%lf%lf",&p1[i].x,&p1[i].y);

         }

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

         {

             swap(p1[i],p1[n-i]);

         }

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

         {

             p3[i]=p1[i];

         }

         p1[n+]=p1[];

         p3[n+]=p3[];

         p3[]=p3[n];

         m=n;

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

         {

             get(p1[i],p1[i+]);

             cut();

         }

         if(m==) printf("0\n");

         else printf("1\n");

     }

     return ;

 }