#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
#define rep(i, n) for(int i=0;i<(n);++i)
#define rep1(i, n) for(int i=1;i<=(n);i++)
#define ll long long
using mint = modint998244353;
using P = pair<ll,ll>;
using lb = long double;
using T = tuple<ll, ll, ll>;
#ifdef LOCAL
#  include <debug_print.hpp>
#  define dbg(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#  define dbg(...) (static_cast<void>(0))
#endif

int main()
{
    vector<pair<int,int>> pos(4);
    rep(i,4) cin >> pos[i].first >> pos[i].second;
    auto dist = [&](int i, int j) -> ll {
        return (pos[i].first-pos[j].first)*(pos[i].first-pos[j].first)+(pos[i].second-pos[j].second)*(pos[i].second-pos[j].second);
    };
    vector<int> vs(4);
    rep(i,4) vs[i] = i;
    vector<pair<int,int>> vec(3);
    rep(i,3) vec[i] = make_pair(pos[i+1].first-pos[0].first,pos[i+1].second-pos[0].second);
    if(vec[1].first*vec[0].second-vec[1].second*vec[0].first==0 && vec[2].first*vec[0].second-vec[2].second*vec[0].first==0){
        cout << "NO" << endl;
        return 0;
    }
    do{
        ll ab = dist(vs[0],vs[1]);
        ll ac = dist(vs[0],vs[2]);
        ll ad = dist(vs[0],vs[3]);
        ll bc = dist(vs[1],vs[2]);
        ll bd = dist(vs[1],vs[3]);
        ll cd = dist(vs[2],vs[3]);
        ll v1 = ac*bd-ab*cd-ad*bc;
        ll v2 = 4*ad*bc*ab*cd;
        dbg(v1*v1,v2);
        if(v1*v1==v2) {
            cout << "YES" << endl;
            return 0;
        }
    }
    while(next_permutation(vs.begin(),vs.end()));
    cout << "NO" << endl;
    return 0;
}