Bicycle#559
After gathering a bouquet of beautiful wildflowers, the cyclist continued his way to his beloved's house along a straight road. At one point, he rode over a white line drawn across the road. Looking back, he noticed that now both of his wheels were leaving white marks (the line was painted!). Despite this, the cyclist continued along the road. Eventually, he reached the house and stopped with the front wheel resting against a vertical wall. The distance between the white line the cyclist crossed and the wall of the house is . The radii of the front and rear wheels are R_1 and R_2, respectively. The distance between the points where the wheels touch the ground is .
Write a program that determines the number of white dots left on the road by the bicycle wheels.
Assume that the width of the white stripe is very small, so the marks left by the wheels are dots.
A single line contains four integers R_1, R_2, , and (0 < R_1, R_2 \leq 100, 2\sqrt{R_1 R_2} < L \leq 1000, L + R_1 < D \leq 10^9), which define the geometry of the bicycle and the distance from the line to the wall.
Output a single integer — the number of white dots left by the bicycle on the road.
Example 1