#include <iostream>
using namespace std;
struct punct
{
double x;
double y;
};
double sarrus(punct A, punct B, punct C)
{
return abs((A.x*B.y + B.x*C.y + C.x*A.y - (C.x*B.y + A.x*C.y + A.y*B.x)) / 2);
}
punct a, b, c, p;
int main()
{
cin >> a.x >> a.y;
cin >> b.x >> b.y;
cin >> c.x >> c.y;
cin >> p.x >> p.y;
if (sarrus(a, b, p) + sarrus(b, c, p) + sarrus(a, c, p) == sarrus(a, b, c))
cout << "este in interiorul triunghiului";
else cout << "nu este in interiorul triunghiului";
return 0;
}
