Description: You are given a sequence of integers a1, a2, ..., an. Let $$f(x,n) = x \bmod a_n$$, and $$f(x,i) = (x \bmod a_i) + f(x \bmod a_i, i+1)$$ for 1 ≤ i < n. Here, $$\bmod$$ denotes the modulus operation. Find the maximum value of f(x, 1) over all nonnegative integers x. Input Format: The first line contains a single integer n (1 ≤ n ≤ 200000) — the length of the sequence. The second lines contains n integers a1, a2, ..., an (1 ≤ ai ≤ 1013) — the elements of the sequence. Output Format: Output a single integer — the maximum value of f(x, 1) over all nonnegative integers x. Note: In the first example you can choose, for example, x = 19. In the second example you can choose, for example, x = 3 or x = 2.