#include <iostream>

#include <stdio.h>

#include <math.h>

using namespace std;

double pi = acos(-1.0);

double x,y,l,w,s,h;

double cal(double a)

{

s = l*cos(a)+w*sin(a)-x;

h = s*tan(a)+w*cos(a);

return h;

}

int main()

{

double left,right,mid,midmid;

while(scanf("%lf%lf%lf%lf",&x,&y,&l,&w)!=EOF)

{

left = 0.0;

right = pi/2;

while(fabs(right-left)>1e-8)

{

mid = (left+right)/2;

midmid = (mid+right)/2;

if(cal(mid)>=cal(midmid))right = midmid;

else left = mid;

}

if(cal(mid)<=y)printf("yes\n");

else printf("no\n");

}

return 0;

}