#include <iostream>
using namespace std; 

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