#include <bits/stdc++.h>
using namespace std;

void ans(bool f) {
  cout << (f ? "YES" : "NO") << endl;
}

int main() {
  double x, y;
  while (cin >> x >> y) {
    vector<pair<int, int>> in;
    in.push_back(make_pair((int)(10.0 * x), (int)(10.0 * y)));
    for (int i = 0; i < 3; ++i) {
      cin >> x >> y;
      in.push_back(make_pair((int)(10.0 * x), (int)(10.0 * y)));
    }

    int dx1 = in[0].first - in[1].first;
    int dy1 = in[0].second - in[1].second;
    int dx2 = in[2].first - in[3].first;
    int dy2 = in[2].second - in[3].second;

    if (dx1 == 0) {
      ans(dy2 == 0);
      break;
    } else if (dx2 == 0) {
      ans(dy1 == 0);
      break;
    }

    ans(dy1 * dy2 == dx1 * dx2 * -1);
  }
}