#include #define rep(i,n) for (ll i = 0; i < n; ++i) #define sz(x) int(x.size()) #define ALL(c) (c).begin(), (c).end() #define SUM(x) std::accumulate(ALL(x), 0LL) #define MIN(v) *std::min_element(v.begin(), v.end()) #define MAX(v) *std::max_element(v.begin(), v.end()) #define EXIST(v, x) (std::find(v.begin(), v.end(), x) != v.end()) #define FORV(i, v) for (auto i = v.begin(); i != v.end(); i++) using namespace std; using ll = long long; template inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; } template inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; } const int INF = 1001001001; const long long INFLL = LLONG_MAX / 3; const double eps = (1e-9); int main() { cin.tie(0); ios::sync_with_stdio(false); ll l, r, m, k; cin >> l >> r >> m >> k; ll n = 0; int a = l % m; int b = r % m; if (k == 0) { puts("Yes"); } else if ((a <= b && b * k < m)) { puts("No"); } else { puts("Yes"); } return 0; }