I have WA 5 again and again. I tried all the test from this forum. I use neither double nor float, but still WA. I don't  know how to deal with it. Can you give me some tests with answers?

Oh, finally! AC! To all, who have WA5: try this test
2 1
0.13
Correct answer is 8.

Thank You very much!!! It's really very useful test! :)