#include using namespace std; typedef long long ll; #define rep(i, n) for(ll i = 0, i##_len = (n); i < i##_len; i++) #define reps(i, s, n) for(ll i = (s), i##_len = (n); i < i##_len; i++) #define rrep(i, n) for(ll i = (n) - 1; i >= 0; i--) #define rreps(i, e, n) for(ll i = (n) - 1; i >= (e); i--) #define all(x) (x).begin(), (x).end() #define rall(x) (x).rbegin(), (x).rend() #define sz(x) ((ll)(x).size()) #define len(x) ((ll)(x).length()) #define endl "\n" int main() { cin.tie(0); ios::sync_with_stdio(false); // ifstream in("input.txt"); // cin.rdbuf(in.rdbuf()); ll l, r, m, k; cin >> l >> r >> m >> k; if ((k == 0) || (m == 1)) { cout << "Yes" << endl; return 0; } ll rc = (r * k) / m; ll lc = (l * k) / m; if (rc != lc) cout << "Yes" << endl; else cout << "No" << endl; return 0; }