1 #include <iostream>
 2 #include <cmath>
 3 using namespace std;
 4 double x,y,l,d;
 5 
 6 double f_angle(double angle)
 7 {
 8     return l*cos(angle)+d/sin(angle)-x/tan(angle);
 9 }
10 
11 int main()
12 {
13     double mid1,mid2,low,high;
14     while(cin>>x>>y>>l>>d)
15     {
16         low=0.0;
17         high=acos(-1.0)/2;
18         while(high-low>=1.0e-6)
19         {
20             //三分法求极值
21             mid1=low+(high-low)/3.0;
22             mid2=high-(high-low)/3.0;
23             if(f_angle(mid1)<=f_angle(mid2))
24                 low=mid1;
25             else
26                 high=mid2;
27         }
28         if(f_angle(low)<y)
29             cout<<"yes"<<endl;
30         else
31             cout<<"no"<<endl;
32     }
33     return 0;
34 }