import java.util.*;
import java.nio.*;
public class Main{
    public static void main(String[] args){
        Solve s=new Solve();s.solve();s.exit();
    }
}
class Solve{
    class pos{
        int x,y;
        pos(int x,int y){
            this.x=x;
            this.y=y;
        }   
    }
    public Scanner sc=new Scanner(System.in);
    void exit(){
        sc.close();
    }
    void swap(int[] v,int x,int y){
        v[x]^=v[y];
        v[y]^=v[x];
        v[x]^=v[y];
    }
    public class comp implements Comparator<pos> {
        int _pos(pos v){
            if (v.y < 0) return -1;
            if (v.y == 0 && 0 <= v.x) return 0;
            return 1;
        }
        @Override
        public int compare(pos s,pos t){
            if(_pos(s)!=_pos(t))return _pos(s)<_pos(t)?1:-1;
            else return 0<s.y*t.x-s.x*t.y?1:-1;
        }
    }
    
    void solve(){
        int n=sc.nextInt();
        int x[],y[];
        x=new int[n];
        y=new int[n];
        for(int i=0;i<n;++i){
            x[i]=sc.nextInt();
            y[i]=sc.nextInt();
        }
        long ans=0;
        for(int i=0;i<n;++i){
            ArrayList<pos>q=new ArrayList<>();
            for(int j=0;j<n;++j){
                if(x[i]==x[j]&&y[i]==y[j])continue;
                q.add(new pos(x[j]-x[i],y[j]-y[i]));
            }
            Collections.sort(q,new comp());
            int l=0,r=0;
            while((int)(l+q.size())!=0&&q.get(0).x*q.get((l+q.size())%q.size()).y-q.get(0).y*q.get((l+q.size())%q.size()).x==0)l--;
            for(int j=0;j<q.size();++j){
                if(j!=0 && q.get(j).x*q.get(j-1).y-q.get(j).y*q.get(j-1).x!=0)l=j-1;
                while(r!=(int)(j+q.size())&&q.get(j).x*q.get(r%q.size()).y-q.get(j).y*q.get(r%q.size()).x>=0)r++;
                ans+=(r-l)*(x[i]*(y[i]+q.get(j).y)-y[i]*(x[i]+q.get(j).x));
            }
        }
        System.out.println(ans);
    }
}