B'You are given array a of length n . You can choose one segment [l, r] ( 1 <= l <= r <= n ) and integer value k (positive, negative or even zero) and change a_l, a_{l + 1}, ... , a_r by k each (i.e. a_i := a_i + k for each l <= i <= r ). What is the maximum possible number of elements with value c that can be obtained after one such operation? The first line contains two integers n and c ( 1 <= n <= 5 cdot 10^5 , 1 <= c <= 5 cdot 10^5 ) -- the length of array and the value c to obtain. The second line contains n integers a_1, a_2, ... , a_n ( 1 <= a_i <= 5 cdot 10^5 ) -- array a . Print one integer -- the maximum possible number of elements with value c which can be obtained after performing operation described above. In the first example we can choose any segment and k = 0 . The array will stay same. In the second example we can choose segment [1, 3] and k = -4 . The array will become [2, -2, 2] . '...