B"You are given a permutation of integers from 1 to n. Exactly once you apply the following operation to this permutation: pick a random segment and shuffle its elements. Formally: Inversion if a pair of elements (not necessary neighbouring) with the wrong relative order. In other words, the number of inversion is equal to the number of pairs (i, xe2 x80 x89j) such that i xe2 x80 x89< xe2 x80 x89j and ai xe2 x80 x89> xe2 x80 x89aj. Find the expected number of inversions after we apply exactly one operation mentioned above. The first line contains a single integer n (1 xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89n xe2 x80 x89 xe2 x89 xa4 xe2 x80 x89100 xe2 x80 x89000) -- the length of the permutation. The second line contains n distinct integers from 1 to n -- elements of the permutation. Print one real value -- the expected number of inversions. Your answer will be considered correct if its absolute or relative error does not exceed 10 xe2 x80 x89- xe2 x80 x899. Namely: let's assume that your answer is a, and the answer of the jury is b. The checker program will consider your answer correct, if . "...