#include <complex>
#include <iostream>
using namespace std;
using ll=long long;
using ull=unsigned long long;

/*#include <atcoder/all>
using namespace atcoder;
using mint=modint998244353;*/

#define rep(i, e) for(int i=0; i<(int)(e); ++i)
#define dir(dx, dy) for(auto [dx, dy]: vector{pair{1, 0}, {0, 1}, {-1, 0}, {0, -1}})

#define all(v) (v).begin(), (v).end()
#define all_r(v) (v).rbegin(), (v).rend()

#define in(i) cin >> i
#define in_d(type, i) type i; cin >> i
#define in_z(i) cin >> i; --i
#define in_d_z(type, i) type i; cin >> i; --i
#define out(i) cout << (i) << endl
#define err(i) cerr << (i) << endl
#define out_e() cout << endl
#define err_e() cerr << endl
#define out_s(i) cout << (i) << " "
#define err_s(i) cerr << (i) << " "

#define out_f(i) cout << fixed << setprecision(15) << (i) << endl
#define err_f(i) cerr << fixed << setprecision(15) << (i) << endl
#define out_fs(i) cout << fixed << setprecision(15) << (i) << " "
#define err_fs(i) cerr << fixed << setprecision(15) << (i) << " "

constexpr int max32=1'000'000'000;
constexpr ll max64=1'000'000'000'000'000'000;

template <typename T>
bool chmin(T & l, const T & r) {
    if(r<l){
        l=r;
        return true;
    }
    return false;
}
template <typename T>
bool chmax(T & l, const T & r) {
    if(r>l){
        l=r;
        return true;
    }
    return false;
}

int main(void) {
    in_d(int, a_x);
    in_d(int, a_y);
    in_d(int, b_x);
    in_d(int, b_y);
    in_d(int, c_x);
    in_d(int, c_y);
    in_d(int, d_x);
    in_d(int, d_y);
    complex<ll> a{a_x, a_y};
    complex<ll> b{b_x, b_y};
    complex<ll> c{c_x, c_y};
    complex<ll> d{d_x, d_y};
    auto l=(b-c)*(a-d);
    auto r=(b-d)*(a-c);
    if(l.real()*r.imag()==l.imag()*r.real()){
        auto d1=b-a;
        auto d2=c-b;
        if(d1.real()*d2.imag()==d1.imag()*d2.real()){
            out("NO");
        } else {
            out("YES");
        }
    } else {
        out("NO");
    }
    return 0;
}