triangle and point

#include <bits/stdc++.h>
using namespace std;

struct point{
    double x,y;
} A, B, C, D;

double s1, s2, s3, s;

double sqr(double x) {
    return x*x;
}

double dist(point A, point B){
    return sqrt(sqr(B.x-A.x)+sqr(B.y-A.y));
}

double tr(point A, point B, point C){
    double a,b,c,p;
    a=dist(A,B);
    b=dist(B,C);
    c=dist(A,C);
    p=(a+b+c)/2;
    return sqrt(p*(p-a)*(p-b)*(p-c));
}

int main()
{
    cin >> A.x >> A.y >> B.x >> B.y >> C.x >> C.y >> D.x >> D.y;

    s=tr(A,B,C);
    s1=tr(A,B,D);
    s2=tr(B,C,D);
    s3=tr(A,C,D);

    cout << ((s>s1+s2+s3-0.0001)?"In":"Out");

    return 0;
}