#include <algorithm>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <ctime>
#include <iostream>
#include <sstream>
#include <functional>
#include <map>
#include <string>
#include <cstring>
#include <vector>
#include <queue>
#include <stack>
#include <deque>
#include <set>
#include <list>
#include <numeric>
using namespace std;
const double PI = 3.14159265358979323846;
const double EPS = 1e-6;
const int INF = 1<<25;
typedef pair<double,int> P;
typedef long long ll;
typedef unsigned long long ull;

int X[5], Y[5];

int main(){
	for(int i = 0; i < 5; i++) cin>>X[i]>>Y[i];
	bool res = true;
	for(int i = 0; i < 5; i++){
		vector<double> d;
		for(int j = 0; j < 5; j++){
			if(i==j) continue;
			int x = X[j]-X[i], y = Y[j]-Y[i];
			d.push_back(atan2(y, x));
		}
		sort(d.begin(), d.end());
		bool ok = (d[3]-d[0])+EPS<PI;
		for(int i = 0; i < 3; i++){
			d[i] += 2*PI;
			ok |= (d[i]-d[i+1])+EPS<PI;
		}
		res &= ok;
	}
	cout<<(res?"YES":"NO")<<endl;
	return 0;
}