#include <iostream>
using namespace std; 

int main()
{
	int a, b, c, d;
	cin >> a >> b >> c >> d;
	int s1 = a - b;
	int s2 = a - c;
	int s3 = b - c;
	if(s1<0) s1=-s1;
	if(s2<0) s2=-s2;
	if(s3<0) s3=-s3;
	if(s2 <= d) cout << "Yes";
	else if(s1 <= d && s3 <= d) cout << "Yes";
	else cout << "No";
	
	return 0;
}