#line 1 "library/Template/template.hpp"
#include <bits/stdc++.h>
using namespace std;

#define rep(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define ALL(v) (v).begin(),(v).end()
using ll=long long int;
const int inf = 0x3fffffff;
const ll INF = 0x1fffffffffffffff;
template<typename T>inline bool chmax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
template<typename T>inline bool chmin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
#line 2 "library/Utility/fastio.hpp"
#include <unistd.h>

class FastIO{
    static constexpr int L=1<<16;
    char rdbuf[L];
    int rdLeft=0,rdRight=0;
    inline void reload(){
        int len=rdRight-rdLeft;
        memmove(rdbuf,rdbuf+rdLeft,len);
        rdLeft=0,rdRight=len;
        rdRight+=fread(rdbuf+len,1,L-len,stdin);
    }
    inline bool skip(){
        for(;;){
            while(rdLeft!=rdRight and rdbuf[rdLeft]<=' ')rdLeft++;
            if(rdLeft==rdRight){
                reload();
                if(rdLeft==rdRight)return false;
            }
            else break;
        }
        return true;
    }
    template<typename T,enable_if_t<is_integral<T>::value,int> =0>inline bool _read(T& x){
        if(!skip())return false;
        if(rdLeft+20>=rdRight)reload();
        bool neg=false;
        if(rdbuf[rdLeft]=='-'){
            neg=true;
            rdLeft++;
        }
        x=0;
        while(rdbuf[rdLeft]>='0' and rdLeft<rdRight){
            x=x*10+(neg?-(rdbuf[rdLeft++]^48):(rdbuf[rdLeft++]^48));
        }
        return true;
    }
    template<typename T,enable_if_t<is_floating_point<T>::value,int> =0>inline bool _read(T& x){
        if(!skip())return false;
        if(rdLeft+20>=rdRight)reload();
        bool neg=false;
        if(rdbuf[rdLeft]=='-'){
            neg=true;
            rdLeft++;
        }
        x=0;
        while(rdbuf[rdLeft]>='0' and rdbuf[rdLeft]<='9' and rdLeft<rdRight){
            x=x*10+(rdbuf[rdLeft++]^48);
        }
        if(rdbuf[rdLeft]!='.')return true;
        rdLeft++;
        T base=.1;
        while(rdbuf[rdLeft]>='0' and rdbuf[rdLeft]<='9' and rdLeft<rdRight){
            x+=base*(rdbuf[rdLeft++]^48);
            base*=.1;
        }
        if(neg)x=-x;
        return true;
    }
    inline bool _read(char& x){
        if(!skip())return false;
        if(rdLeft+1>=rdRight)reload();
        x=rdbuf[rdLeft++];
        return true;
    }
    inline bool _read(string& x){
        if(!skip())return false;
        for(;;){
            int pos=rdLeft;
            while(pos<rdRight and rdbuf[pos]>' ')pos++;
            x.append(rdbuf+rdLeft,pos-rdLeft);
            if(rdLeft==pos)break;
            rdLeft=pos;
            if(rdLeft==rdRight)reload();
            else break;
        }
        return true;
    }
    template<typename T>inline bool _read(vector<T>& v){
        for(auto& x:v){
            if(!_read(x))return false;
        }
        return true;
    }

    char wtbuf[L],tmp[50];
    int wtRight=0;
    inline void flush(){
        fwrite(wtbuf,1,wtRight,stdout);
        wtRight=0;
    }
    inline void _write(const char& x){
        if(wtRight>L-32)flush();
        wtbuf[wtRight++]=x;
    }
    inline void _write(const string& x){
        for(auto& c:x)_write(c);
    }
    template<typename T,enable_if_t<is_integral<T>::value,int> =0>inline void _write(T x){
        if(wtRight>L-32)flush();
        if(x==0){
            _write('0');
            return;
        }
        else if(x<0){
            _write('-');
            if (__builtin_expect(x == std::numeric_limits<T>::min(), 0)) {
                switch (sizeof(x)) {
                case 2: _write("32768"); return;
                case 4: _write("2147483648"); return;
                case 8: _write("9223372036854775808"); return;
                }
            }
            x=-x;
        }
        int pos=0;
        while(x!=0){
            tmp[pos++]=char((x%10)|48);
            x/=10;
        }
        rep(i,0,pos)wtbuf[wtRight+i]=tmp[pos-1-i];
        wtRight+=pos;
    }
    template<typename T>inline void _write(const vector<T>& v){
        rep(i,0,v.size()){
            if(i)_write(' ');
            _write(v[i]);
        }
    }
public:
    FastIO(){}
    ~FastIO(){flush();}
    inline void read(){}
    template <typename Head, typename... Tail>inline void read(Head& head,Tail&... tail){
        assert(_read(head));
        read(tail...); 
    }
    template<bool ln=true,bool space=false>inline void write(){if(ln)_write('\n');}
    template <bool ln=true,bool space=false,typename Head, typename... Tail>inline void write(const Head& head,const Tail&... tail){
        if(space)_write(' ');
        _write(head);
        write<ln,true>(tail...); 
    }
};

/**
 * @brief Fast IO
 */
#line 3 "sol.cpp"

struct Point{
    ll X,Y;
    Point():X(0),Y(0){}
    Point(ll _X,ll _Y):X(_X),Y(_Y){}
    int pos()const{
        if(Y<0)return -1;
        if(Y==0 and 0<=X)return 0;
        return 1;
    }
    Point& operator+=(const Point& p){
        X+=p.X;
        Y+=p.Y;
        return *this;
    }
    Point& operator-=(const Point& p){
        X-=p.X;
        Y-=p.Y;
        return *this;
    }
    Point operator+(const Point &p) const { return Point(*this) += p; }
    Point operator-(const Point &p) const { return Point(*this) -= p; }
    Point operator-() const { return Point(-X, -Y); }
    bool operator==(const Point &p) const { return X == p.X && Y == p.Y; }
    bool operator!=(const Point &p) const { return X != p.X || Y != p.Y; }
    bool operator<(const Point &p) const { return X == p.X ? Y < p.Y : X < p.X; }
};
using Poly=vector<Point>;

ll dot(const Point &a, const Point &b) { return a.X * b.X + a.Y * b.Y; }
ll cross(const Point &a, const Point &b) { return a.X * b.Y - a.Y * b.X; }
bool cmp(const Point& a,const Point& b){
    if(a.pos()!=b.pos())return a.pos()<b.pos();
    return a.Y*b.X<a.X*b.Y;
}
int ccw(const Point& a,Point b,Point c){
    b-=a; c-=a;
    ll C=cross(b,c);
    if(C>0)return 1; //ccw
    if(C<0)return -1; //cw
    if(dot(b,c)<0)return 2; //c,a,b
    if(dot(b,b)<dot(c,c))return -2; //a,b,c
    return 0; //a,c,b
}

int isContained(const Poly& a,const Point& b){
    bool res=0;
    int n=a.size();
    rep(i,0,n){
        Point p=a[i]-b,q=a[(i+1)%n]-b;
        if(p.Y>q.Y)swap(p,q);
        if(p.Y<0 and 0<q.Y and cross(p,q)>0)res^=1;
        if(cross(p,q)==0 and dot(p,q)<0)return 1;
    }
    return (res?2:0);
}
Poly ConvexHull(Poly& a){
    int n=a.size(),k=0;
    sort(ALL(a),[](const Point& p,const Point& q){
        return (p.Y==q.Y?p.X<q.X:p.Y<q.Y);
    });
    Poly res(n*2);
    for(int i=0;i<n;res[k++]=a[i++]){
        while(k>=2 and cross(res[k-1]-res[k-2],a[i]-res[k-1])<=0)k--;
    }
    for(int i=n-2,t=k+1;i>=0;res[k++]=a[i--]){
        while(k>=t and cross(res[k-1]-res[k-2],a[i]-res[k-1])<=0)k--;
    }
    res.resize(k-1); return res;
}


FastIO io;
int main(){
    Poly a(5);
    rep(i,0,5)io.read(a[i].X,a[i].Y);

    auto C=ConvexHull(a);
    if(C.size()==5)io.write("YES");
    else io.write("NO");
    return 0;
}