B"You are given an array consisting of n integers a_1, a_2, ... , a_n and an integer x . It is guaranteed that for every i , 1 <= a_i <= x . Let's denote a function f(l, r) which erases all values such that l <= a_i <= r from the array a and returns the resulting array. For example, if a = [4, 1, 1, 4, 5, 2, 4, 3] , then f(2, 4) = [1, 1, 5] . Your task is to calculate the number of pairs (l, r) such that 1 <= l <= r <= x and f(l, r) is sorted in non-descending order. Note that the empty array is also considered sorted. The first line contains two integers n and x ( 1 <= n, x <= 10^6 ) -- the length of array a and the upper limit for its elements, respectively. The second line contains n integers a_1, a_2, ... a_n ( 1 <= a_i <= x ). Print the number of pairs 1 <= l <= r <= x such that f(l, r) is sorted in non-descending order. In the first test case correct pairs are (1, 1) , (1, 2) , (1, 3) and (2, 3) . In the second test case correct pairs are (1, 3) , (1, 4) , (2, 3) , (2, 4) , (3, 3) and (3, 4) . "...