#include<iostream>
#include<algorithm>
using namespace std;
int main()
{
    int a[3],d;
    cin>>a[0]>>a[1]>>a[2]>>d;
    sort(a,a+3);
    
    
    if (a[1]-a[0]<=d && a[2]-a[1]<=d)
    cout<<"Yes\n";
    else cout<<"No\n";
    return 0;
}