#include<bits/stdc++.h>
#define inf 0x3f3f3f3f3f3f3f3fll
#define debug(x) cerr<<#x<<"="<<x<<endl
using namespace std;
using ll=long long;
using ld=long double;
using pli=pair<ll,int>;
using pi=pair<int,int>;
template<typename A>
using vc=vector<A>;
template<typename A,const int N>
using aya=array<A,N>;
inline int read()
{
    int s=0,w=1;char ch;
    while((ch=getchar())>'9'||ch<'0') if(ch=='-') w=-1;
    while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
    return s*w;
}
inline ll lread()
{
    ll s=0,w=1;char ch;
    while((ch=getchar())>'9'||ch<'0') if(ch=='-') w=-1;
    while(ch>='0'&&ch<='9') s=s*10+ch-'0',ch=getchar();
    return s*w;
}
const int mod=10000007;
const int base=137;
ll B[10];
struct Hash
{
    int head[10000010];
    ll v1[2000010],v2[2000010];
    int nx[2000010];
    int cnt;ll C1,C2;
    inline void ins(ll g,int v)
    {
        if(!v) return ;
        int u=g%mod;
        for(int i=head[u];i;i=nx[i]) if(v1[i]==g)  
        {
            v2[i]+=v;
            return ;
        }
        else C2++;
        cnt++,v1[cnt]=g,v2[cnt]=v;
        nx[cnt]=head[u],head[u]=cnt;
    }
    inline void ins(int a,int b,int c,int d,int e,int f,int v)
    {
        if(!v) return ;
        ll g=0;C1++;
        g=g*base+a;g=g*base+b;g=g*base+c;g=g*base+d;g=g*base+e;g=g*base+f;
        ins(g,v);
    }
    inline void clear()
    {
        cnt=C1=C2=0;
        memset(head,0,sizeof(head));
    }
}tp[2];
ll dp[2][45][45],fp[2][45][45];
struct node{ ld x,y;}a[45];
int n;
inline bool check(int x,int y,int z)
{
    if(!x||!z) return true;
    ld x1=a[y].x-a[x].x,y1=a[y].y-a[x].y;
    ld x2=a[z].x-a[y].x,y2=a[z].y-a[y].y;
    return x1*y2-x2*y1>=0;
}
int main()
{
    n=read();
    for(int i=1;i<=n;i++) a[i].x=read(),a[i].y=read();
    sort(a+1,a+n+1,[](node a,node b)
    {
        if(a.y!=b.y) return a.y<b.y;
        return a.x<b.x;
    });
    sort(a+2,a+n+1,[](node b,node c)
    {
        ld x1=b.x-a[1].x,y1=b.y-a[1].y,z1=sqrtl(x1*x1+y1*y1);
        ld x2=c.x-a[1].x,y2=c.y-a[1].y,z2=sqrtl(x2*x2+y2*y2);
        return x1/z1>x2/z2;
    });
    B[0]=1;
    for(int i=1;i<=5;i++) B[i]=B[i-1]*base;
    int now=0,lst=1;dp[now][1][0]=1;

    for(int i=2;i<=n;i++)
    {
        //加入点 i
        swap(now,lst);
        memset(dp[now],0,sizeof(dp[now]));
        memset(fp[now],0,sizeof(fp[now]));
        tp[now].clear();

        for(int x=0;x<=i;x++) for(int y=0;y<=i;y++)
        {
            //dp[x][y] and fp[x][y]
            if(check(y,x,i))
            {
                dp[now][i][x]+=dp[lst][x][y];
                fp[now][i][x]+=fp[lst][x][y];
            }
            fp[now][x][y]+=dp[lst][x][y];
            tp[now].ins(x,y,i,0,i,0,dp[lst][x][y]);
        }
        for(int j=1;j<=tp[lst].cnt;j++)
        {
            ll v=tp[lst].v2[j],id=tp[lst].v1[j],g=id;
            int a,b,c,d,e,f;
            f=g%base,g/=base;e=g%base,g/=base;d=g%base,g/=base;
            c=g%base,g/=base;b=g%base,g/=base;a=g%base,g/=base;

            bool f1=0,f2=0;
            if(check(b,a,i)) tp[now].ins(i,a,c,d,e,f,v);
            if(check(d,c,i)) tp[now].ins(a,b,i,c,e,f?f:i,v),f1=1;
            if(check(i,e,f)) tp[now].ins(a,b,c,d?d:i,i,e,v),f2=1;
            if(f1&&f2)
            {
                fp[now][a][b]+=v;
                // printf("(%d,%lld)%d %d %d %d %d %d + %d v=%lld -> fp %d %d\n",j,tp[lst].v1[j],a,b,c,d,e,f,i,v,a,b);
            }
        }

        // ll ans=0;
        // for(int i=0;i<=n;i++) for(int j=0;j<=n;j++) if(check(j,i,1)) ans+=dp[now][i][j]+fp[now][i][j];
        // printf("i=%d : %Lf %Lf %d  (%lld,%lld) %lld\n",i,a[i].x,a[i].y,tp[now].cnt,tp[now].C1,tp[now].C2,ans);

        // for(int x=0;x<=n;x++) for(int y=0;y<=n;y++) if(dp[now][x][y]) printf("dp[%d][%d]=%lld\n",x,y,dp[now][x][y]);
        // for(int x=0;x<=n;x++) for(int y=0;y<=n;y++) if(fp[now][x][y]) printf("fp[%d][%d]=%lld\n",x,y,fp[now][x][y]);
        // for(int j=1;j<=tp[now].cnt;j++)
        // {
        //     ll v=tp[now].v2[j],g=tp[now].v1[j];
        //     int a,b,c,d,e,f;
        //     f=g%base,g/=base;e=g%base,g/=base;d=g%base,g/=base;
        //     c=g%base,g/=base;b=g%base,g/=base;a=g%base,g/=base;
        //     printf("tp %d %d %d %d %d %d : %lld\n",a,b,c,d,e,f,v);
        // }
    }
    ll ans=0;
    for(int i=0;i<=n;i++) for(int j=0;j<=n;j++) if(check(j,i,1))
    {
        ans+=dp[now][i][j]+fp[now][i][j];
        // if(dp[now][i][j]) printf("ans dp[%d][%d]=%lld\n",i,j,dp[now][i][j]);
        // if(fp[now][i][j]) printf("ans fp[%d][%d]=%lld\n",i,j,fp[now][i][j]);
    }
    printf("%lld\n",ans*2);
    return 0;
}