#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cmath>
const int mx = 60;
using namespace std;
typedef struct poi{
  double x;
  double y;
  poi(double a = 0, double b = 0){
  	x = a; y = b;
  }
  
  poi operator + (const poi a) const{
   	return poi(x+a.x, y+a.y);
  }
  
  poi operator - (const poi a) const{
  	return poi(x-a.x, y-a.y);
  }
  
  double operator * (const poi a) const{
  	return (x*a.x + y*a.y);
  }
  
  poi operator * (const  double a) const{
  	return poi(x*a , y*a);                              //这里重载错了直接爆炸一直wa，逗号写成加号 
  }
  
  double operator ^(const poi a) const{
  	return(x*a.y - y*a.x);
  }
  
}vec;
poi P[mx], S[mx*10], T[mx*10];
int n;
 
int dbcmp(double a){
	return fabs(a)<(1e-6)?0:(a>0?1:-1);
}
 
poi getline(poi p, vec v, poi q, vec w){
	vec u = p - q;
	double t = (w^u)/(v^w);
	return p+v*t;
}
 
bool judge(){
	for(int i = 0; i < n; i++){
		S[i] = P[i];
	}
	int num1 = n, add;
	
	for(int i = 0; i < n; i++){
		 add = 0;
		for(int j = 0; j < num1; j++){ 
			int ans1 = dbcmp((P[(i+1)%n]-P[i]) ^ (S[j]-P[i]));
			int ans2 = dbcmp((P[(i+1)%n]-P[i]) ^ (S[(j+1)%num1]-P[i]));
			
			if(ans1 >= 0)
			   T[add++] = S[j];
			if(ans1 * ans2 < 0)
			   T[add++] = getline(P[i], (P[(i+1)%n]-P[i]), S[j], (S[(j+1)%num1]-S[j]));
		} 
		
		for(int k = 0; k < add; k++){
			S[k] = T[k];
		}
		num1 = add;
	}
	
	return num1 != 0;
}
 
int main(){
	while(scanf("%d",&n) && n){
	
		for(int i = 0; i < n; i++){
			scanf("%lf%lf", &P[i].x, &P[i].y);
		}
		
		if(judge()) puts("1");
		else puts("0"); 
	}
	
	return 0;
}