You are given a sequence a consisting of n integers. Find the maximum possible value of (integer remainder of a i divided by a j ), where 1 ≤ i, j ≤ n and a i ≥ a j .
输入描述:
The first line contains integer n — the length of the sequence (1 ≤ n ≤ 2·105). The second line contains n space-separated integers ai (1 ≤ ai ≤ 106).