B"A permutation of length n is an integer sequence such that each integer from 0 to (n xe2 x80 x89- xe2 x80 x891) appears exactly once in it. For example, sequence [0, xe2 x80 x892, xe2 x80 x891] is a permutation of length 3 while both [0, xe2 x80 x892, xe2 x80 x892] and [1, xe2 x80 x892, xe2 x80 x893] are not. A fixed point of a function is a point that is mapped to itself by the function. A permutation can be regarded as a bijective function. We'll get a definition of a fixed point in a permutation. An integer i is a fixed point of permutation a0, xe2 x80 x89a1, xe2 x80 x89..., xe2 x80 x89an xe2 x80 x89- xe2 x80 x891 if and only if ai xe2 x80 x89= xe2 x80 x89i. For example, permutation [0, xe2 x80 x892, xe2 x80 x891] has 1 fixed point and permutation [0, xe2 x80 x891, xe2 x80 x892] has 3 fixed points. You are given permutation a. You are allowed to swap two elements of the permutation at most once. Your task is to maximize the number of fixed points in the resulting permutation. Note that you are allowed to make at most one swap operation. 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 x89105). The second line contains n integers a0, xe2 x80 x89a1, xe2 x80 x89..., xe2 x80 x89an xe2 x80 x89- xe2 x80 x891 -- the given permutation. Print a single integer -- the maximum possible number of fixed points in the permutation after at most one swap operation."...