#include <bits/stdc++.h>
using namespace std;
long long a,b,c,s,x1,y1,x2,y2,x3,y3;
int main(){
    cin>>x1>>y1>>x2>>y2>>x3>>y3;
    a=abs(pow(x1-x2,2)+pow(y1-y2,2));
    b=abs(pow(x3-x2,2)+pow(y3-y2,2));
    c=abs(pow(x3-x1,2)+pow(y3-y1,2));
    s=0.5*(a+b+c);
    cout<<pow(s*(s-a)*(s-b)*(s-c));
    return 0;
}