#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int main() {
  ll l, r, m, k;
  cin >> l >> r >> m >> k;
  ll n = 0;
  vector<bool> mod(r - l + 1, false);
  if (k == 0) {
    cout << "Yes" << endl;
    return 0;
  }

  for (ll i = l % m; i <= r % m; i++) {
    mod[i] = true;
  }
  ll ans = count(mod.begin(), mod.end(), true);

  if (k == 1 && mod[0] == false) {
    cout << "No" << endl;
    return 0;
  }

  if (ans % k == 0) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
}