I know that maths is an important aspect of competitive programming, But on what aspect a question related to direct * integration* has appeared on long challenge. Never expected this kind of irrelevant question on long challenge. Not every body comes from a proper maths background to solve such questions. This is not a maths olympiad that the problem settler are giving such kind of direct integration.

**Please do not give anything for making the question irrelevant and hard. This is a real disgrace.**.

Do not conduct long challenge if you all cannot give proper questions which are really interesting and challenges a person to be better.