计算车辆的拐弯,Turn the corner

Problem Description
Mr. West bought a new car! So he is travelling around the city.

One day he comes to a vertical corner. The street he is currently in has a width x, the street he wants to turn to has a width y. The car has a length l and a width d.

Can Mr. West go across the corner?

Input
Every line has four real numbers, x, y, l and w.
Proceed to the end of file.

Output
If he can go across the corner, print "yes". Print "no" otherwise.

Sample Input
10 6 13.5 4
10 6 14.5 4

Sample Output
yes
no