#include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #define repr(i, a, b) for (int i = (int)(a); i < (int)(b); i++) #define rep(i, n) repr(i, 0, n) #define INF 2e9 #define MOD 1000000007 //#define MOD 998244353 #define LINF (long long)4e18 #define jck 3.141592 const double EPS = 1e-10; using ll = long long; using Pi = pair; using Pl = pair; int main(){ int l,r,m,k; cin >> l >> r >> m >> k; ll a = (ll)l*k; ll b = (ll)r*k; if(a == 0){ if(b/m == 0) cout << "No" << endl; else cout << "Yes" << endl; return 0; } if(b/m-(a-1)/m == 0){ cout << "No" << endl; } else cout << "Yes" << endl; }