#include<bits/stdc++.h>
using namespace std;
#define LD double 
#define LL long long
#define Vector Point
const int N=2e3+5;
int vis[N];
struct Point{
	LL x,y;int id;Point(LL X=0,LL Y=0){x=X,y=Y;}
	inline Point operator-(const Point &O)const{return Point(x-O.x,y-O.y);}
}P[N],cp[N],B[N],C[N];
inline LL Cro(Vector a,Vector b){return a.x*b.y-a.y*b.x;}
inline bool cmp1(Vector a,Vector b){return a.x==b.x?a.y<b.y:a.x<b.x;};
inline int ConvexHull(Point *P,int n,Point *cp){
    sort(P+1,P+n+1,cmp1);
    for(int i=1;i<=n;++i)P[i].id=i;
    int t=0;
    for(int i=1;i<=n;++i){//ÏÂ͹°ü
        while(t>1&&Cro(cp[t]-cp[t-1],P[i]-cp[t-1])<=0)--t;
        cp[++t]=P[i];
    }
    int St=t;
    for(int i=n-1;i>=1;--i){//ÉÏ͹°ü
        while(t>St&&Cro(cp[t]-cp[t-1],P[i]-cp[t-1])<=0)--t;
        cp[++t]=P[i];
    }
    return --t;
}
inline bool cmp2(Vector a,Vector b){return Cro(a,b)>0;};
inline LD calc(Vector a){return atan2(a.y,a.x);}
int n,m,ans=1;
int main(){
//	freopen("123.txt","r",stdin);
	scanf("%d",&n);
	for(int i=1;i<=n;++i)scanf("%lld%lld",&P[i].x,&P[i].y);
	int cnt=ConvexHull(P,n,cp);
	for(int i=1;i<=cnt;++i)vis[cp[i].id]=1;
	for(int i=1;i<=n;++i)if(!vis[i])B[++m]=P[i];
	for(int i=1;i<=cnt;++i){
		Point a=cp[i],b=cp[i+1];
//		printf("(%lld,%lld) <-> (%lld,%lld):\n",a.x,a.y,b.x,b.y);
		for(int j=1;j<=m;++j)C[j]=B[j]-a,C[j].id=j;
		sort(C+1,C+m+1,cmp2);
//		for(int j=1;j<=m;++j)printf("%lld,%lld\n",C[j].x,C[j].y);
		LD maxk=-1e9;
		for(int j=1;j<=m;++j){
			LD tmpk=calc(B[C[j].id]-b);
			if(tmpk>=maxk)++ans,maxk=tmpk;
		}
	}
	printf("%d\n",ans);
}