I am getting a wrong answer in FLOW009

I can’t understand where I am getting it wrong…
This is my submission: https://www.codechef.com/viewsolution/27158939

Check for test case
1
100000 100000

Your answer:

8999999488.000000

Right answer:

9000000000.000000

Hint

Change float to double.

Hope this helps.

Thanks a lot!!! I got it.