smin

#include <fstream>
#include <cmath>
#include <iomanip>
#define MAX1 20
#define MAX2 1<<20
#define INFINIT 1E20
using namespace std;
ifstream f("smin.in");
ofstream g("smin.out");
double s[MAX2];
int i,j,k,l,m,n,z;
double tr;
struct Punct
{
    int x,y;
} p[MAX1];

double Aria(Punct p1,Punct p2,Punct p3) /// dublul ariei triunghiului
{
	return (p1.x-p2.x)*(p1.y+p2.y)+(p2.x-p3.x)*(p2.y+p3.y)+(p3.x-p1.x)*(p3.y+p1.y);
}

int main()
{
    f>>n;
    for(i=0;i<n;++i)
        f>>p[i].x>>p[i].y;
    m=1<<n;
    s[0]=0.0;
    for(i=1;i<m;++i)
        s[i]=INFINIT;
    for(i=0;i<m;++i)
        for(j=0;j<n;++j)
            for(k=j+1;k<n;++k)
                for(l=k+1;l<n;++l)
                {
                    z=i|(1<<j)|(1<<k)|(1<<l);
                    tr=fabs(Aria(p[j],p[k],p[l]));
                    if (s[z]>s[i]+tr)
						s[z]=s[i]+tr;
                }
    g<<s[m-1]*0.5<<'\n';
    f.close();
    g.close();
    return 0;
}