// B - Battle
#include <bits/stdc++.h>
using namespace std;
int A,B,C,D;

bool solve(){
	int m[2][2]={{A,B},{C,D}};
	int at = 0;
	while(true){
		int df = (at+1)%2;
		m[df][0] -= m[at][1];
		if(m[df][0] <= 0){
			if(df%2) return true;
			return false;
		}
		at = df;
	}
	return false;
}

int main(){
	cin>>A>>B>>C>>D;
	cout<< (solve()? "Yes":"No") <<endl;
}
