#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
long long gcd(long long x, long long y){
    if(x < y) swap(x, y);
    if(x % y == 0) return y;
    long long t = y;
    y = x % y;
    x = t;
    return gcd(x, y);  
}
int main(){
    long long L, R, M, K;
    cin >> L >> R >> M >> K;
    if(K == 0){
        cout << "Yes" << endl;
        return 0;
    }
    long long s = gcd(M, K);
    long long t = M / s;
    if(L == 0){
        cout << "Yes" << endl;
        return 0;
    }
    else if(R / t - (L - 1) / t > 0){
        cout << "Yes" << endl;
        return 0;
    }
    cout << "No" << endl;
}