using System;
using System.IO;
using System.Linq;
using System.Text;
using System.Collections.Generic;
using System.Diagnostics;
using System.Numerics;
using Enu = System.Linq.Enumerable;

class Program
{
    public void Solve()
    {
        var vec = Enu.Range(0, 5).Select(i => new Vector2D(Reader.Int(), Reader.Int())).ToList();
        if (ConvexHull(vec).Count == 5) Console.WriteLine("YES");
        else Console.WriteLine("NO");
    }

    List<Vector2D> ConvexHull(List<Vector2D> Ps)
    {
        Ps.Sort();
        var res = new List<Vector2D>();
        for (int i = 0; i < Ps.Count; i++)
        {
            while (res.Count > 1 && (res[res.Count - 1] - res[res.Count - 2]).Det(Ps[i] - res[res.Count - 1]) <= 0)
                res.RemoveAt(res.Count - 1);
            res.Add(Ps[i]);
        }
        for (int i = Ps.Count - 2, t = res.Count; i >= 0; i--)
        {
            while (res.Count > t && (res[res.Count - 1] - res[res.Count - 2]).Det(Ps[i] - res[res.Count - 1]) <= 0)
                res.RemoveAt(res.Count - 1);
            res.Add(Ps[i]);
        }
        res.RemoveAt(res.Count - 1);
        return res;
    }
    struct Vector2D : IEquatable<Vector2D>, IComparable<Vector2D>
    {
        public long X, Y;
        public Vector2D(long x, long y) { X = x; Y = y; }
        public static Vector2D operator +(Vector2D a, Vector2D b)
        {
            return new Vector2D(a.X + b.X, a.Y + b.Y);
        }
        public static Vector2D operator -(Vector2D a, Vector2D b)
        {
            return new Vector2D(a.X - b.X, a.Y - b.Y);
        }
        public long DistSquare(Vector2D b) { return (X - b.X) * (X - b.X) + (Y - b.Y) * (Y - b.Y); }
        public double Dist(Vector2D b) { return Math.Sqrt(DistSquare(b)); }
        public long InnerProduct(Vector2D b) { return X * b.X + Y * b.Y; }
        public long Det(Vector2D b) { return X * b.Y - Y * b.X; }
        public override int GetHashCode() { return (int)(X * 10007 + Y); }
        public bool Equals(Vector2D b) { return X == b.X && Y == b.Y; }
        public int CompareTo(Vector2D b) { return X != b.X ? Math.Sign(X - b.X) : Math.Sign(Y - b.Y); }
    }
}


class Entry { static void Main() { new Program().Solve(); } }
class Reader
{
    private static TextReader reader = Console.In;
    private static readonly char[] separator = { ' ' };
    private static readonly StringSplitOptions op = StringSplitOptions.RemoveEmptyEntries;
    private static string[] A = new string[0];
    private static int i;
    private static void Init() { A = new string[0]; }
    public static void Set(TextReader r) { reader = r; Init(); }
    public static void Set(string file) { reader = new StreamReader(file); Init(); }
    public static bool HasNext() { return CheckNext(); }
    public static string String() { return Next(); }
    public static int Int() { return int.Parse(Next()); }
    public static long Long() { return long.Parse(Next()); }
    public static double Double() { return double.Parse(Next()); }
    public static int[] IntLine() { return Array.ConvertAll(Split(Line()), int.Parse); }
    public static int[] IntArray(int N) { return Enu.Range(0, N).Select(i => Int()).ToArray(); }
    public static int[][] IntTable(int H) { return Enu.Range(0, H).Select(i => IntLine()).ToArray(); }
    public static string[] StringArray(int N) { return Enu.Range(0, N).Select(i => Line()).ToArray(); }
    public static string Line() { return reader.ReadLine().Trim(); }
    private static string[] Split(string s) { return s.Split(separator, op); }
    private static string Next() { CheckNext(); return A[i++]; }
    private static bool CheckNext()
    {
        if (i < A.Length) return true;
        string line = reader.ReadLine();
        if (line == null) return false;
        if (line == "") return CheckNext();
        A = Split(line);
        i = 0;
        return true;
    }
}