23641번 - Array 다국어

문제

You are given an array $a_1, a_2, \ldots, a_n$. Let $x_1 = a_1,ドル and $x_i = x_{i - 1} \bmod a_i$ for each $i$ from 2ドル$ to $n$.

Suppose that we can rearrange $a_1, \ldots, a_n$ in any way. What is the largest possible value of $x_n$ we can obtain?

입력

The first line contains an integer $n$ --- the size of the array (2ドル\leq n\leq 10^5$).

The second line containing $n$ integers $a_1, \ldots, a_n$ (1ドル\leq a_i\leq 10^5$).

출력

Print one integer --- the largest possible value of $x_n$.

제한

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