// Problem B  Ver. 1.0
// Coding & Debug : 25min

#include <stdio.h>

int main()
{
	FILE *fp = fopen("B.txt","r");
	int x,y,k,f,n;
	struct {int x,y;} p[60];
	int x_max=0,y_max=0,x_min=10000*2,y_min=10000*2;

	while(fscanf(fp,"%d",&n) && n) {
		for (k=0;k<n;k++) {
			fscanf(fp,"%d %d",&p[k].x,&p[k].y);
			p[k].x*=2;
			p[k].y*=2;
			if (p[k].x<x_min) x_min = p[k].x;
			if (p[k].y<y_min) y_min = p[k].y;
			if (p[k].x>x_max) x_max = p[k].x;
			if (p[k].y>y_max) y_max = p[k].y;
		}
		p[n].x = p[0].x;
		p[n].y = p[0].y;
		f=0;
		for (y=y_min+1;y<y_max;y+=2) {
			for (x=x_min+1;x<x_max;x+=2) {
				for (k=0;k<n;k++) {
					if ( (p[k+1].x-p[k].x)*(y-p[k].y)
						< (p[k+1].y-p[k].y)*(x-p[k].x) ) break;
				}
				if (k==n) {f=1;break;}
			}
			if (f) break;
		}
		printf("%d\n",f);
	}
	return 0;
}