#include<iostream>
#include<vector>
#include<algorithm>

using namespace std;
using ll = long long;

ll cross(ll a,ll b,ll c,ll d){
    return a * d - c * b;
}

int ccw(pair<ll,ll> a,pair<ll,ll> b,pair<ll,ll> c){
    ll dx = b.first - a.first;
    ll dy = b.second - a.second;
    ll ddx = c.first - b.first;
    ll ddy = c.second - b.second;
    ll now = cross(dx,dy,ddx,ddy);
    if(now>0) return 1;
    if(now<0) return -1;
    return 0;
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int n = 5;
    vector<ll> x(n),y(n);
    for(int i = 0;i<n;i++) cin>>x[i]>>y[i];
    vector<pair<ll,ll>> use;
    for(int i = 0;i<n;i++) use.push_back(make_pair(x[i],y[i]));
    sort(use.begin(),use.end());
    vector<pair<ll,ll>> lower,upper;

    {
        for(int i = 0;i<use.size();i++){
            while(upper.size()>=2){
                int m = upper.size();
                if(ccw(upper[m-2],upper[m-1],use[i])!=-1) upper.pop_back();
                else break;
            }
            upper.push_back(use[i]);
        }
    }
    {
        for(int i = 0;i<use.size();i++){
            while(lower.size()>=2){
                int m = lower.size();
                if(ccw(lower[m-2],lower[m-1],use[i])!=1) lower.pop_back();
                else break;
            }
            lower.push_back(use[i]);
        }
    }
    if(upper.size()+lower.size()==7) cout<<"YES\n";
    else cout<<"NO\n";
}