#include using namespace std; using ll = long long; template struct point{ T x, y; point(): x(0), y(0){} point(T a, T b): x(a), y(b){} point& operator += (const point& rhs) {x += rhs.x, y += rhs.y; return *this;} point& operator -= (const point& rhs) {x -= rhs.x, y -= rhs.y; return *this;} point& operator *= (const T& rhs) {x *= rhs, y *= rhs; return *this;} point& operator /= (const T& rhs) {x /= rhs, y /= rhs; return *this;} point operator +() const { return *this; } point operator -() const { return point() - *this; } friend point operator + (const point& lhs, const point& rhs) {return point(lhs) += rhs;} friend point operator - (const point& lhs, const point& rhs) {return point(lhs) -= rhs;} friend point operator * (const point& lhs, const T& rhs) {return point(lhs) *= rhs;} friend point operator * (const T& lhs, const point& rhs) {return point(rhs) *= lhs;} friend point operator / (const point& lhs, const T& rhs) {return point(lhs) /= rhs;} friend T operator * (const point& lhs, const point& rhs) {return lhs.x * rhs.x + lhs.y * rhs.y;} friend T operator ^ (const point& lhs, const point& rhs) {return lhs.x * rhs.y - lhs.y * rhs.x;} friend bool operator == (const point& lhs, const point& rhs) {return (lhs.x == rhs.x && lhs.y == rhs.y);} friend istream& operator >> (istream& os, point& rhs) noexcept { os >> rhs.x >> rhs.y; return os; } friend constexpr ostream& operator << (ostream &os, const point& rhs) noexcept { return os << '('<< rhs.x << ',' << rhs.y << ')'; } double norm(){return sqrt(x * x + y * y);} T norm2(){return x * x + y * y;} int orthant(){//第何象限かのベクトルを返す(0,0は0象限とする) if(x == 0 && y == 0)return 0; if(y > 0)return (x > 0 ? 1 : 2); return (x > 0 ? 4 : 3); } //偏角ソート->ベクトルの大きさの小さい順の優先度 friend bool operator < (point &lhs, point &rhs){//tupleとかでソートできないときは&を外すと良いかもしれない int lo = lhs.orthant(), ro = rhs.orthant(); if(lo != ro)return (lo < ro); T cv = (lhs ^ rhs); if(cv != 0)return (cv > 0); return (lhs.norm2() < rhs.norm2()); } }; int main(){ ios::sync_with_stdio(false); cin.tie(0); vector> a(4); for(int i = 0; i < 4; i++){ ll x, y, z; cin >> x >> y >> z; a[i] = {x, y, z}; } for(int i = 0; i < 3; i++){ vector> b(4); for(int j = 0; j < 4; j++){ b[j] = {a[j][0], a[j][1]}; rotate(a[j].begin(), a[j].begin() + 1, a[j].end()); } vector c(3); for(int j = 0; j < 3; j++){ c[j] = (b[(j + 1) % 3] - b[j]) ^ (b[3] - b[j]); } sort(c.begin(), c.end()); if(c[0] * c[2] < 0){ cout << "NO\n"; exit(0); } } cout << "YES\n"; }