Given $n$ positive integers $a_i$, choose three indices $i, j, k$ ($i \neq j$, $i \neq k$, $j \neq k$) such that the value of $(a_i + a_j) \pmod{a_k}$ is maximized.
Input
The first line contains an integer $n$, representing the number of integers. The second line contains $n$ integers representing $a_i$.
Output
Output a single integer representing the answer.
Examples
Input 1
6 4 7 7 5 2 2
Output 1
6
Input 2
(See mod/mod2.in)
Output 2
(See mod/mod2.ans)
Constraints
For 30% of the data: $n \leq 100$. For 60% of the data: $n \leq 3000$. For 100% of the data: $2 \leq n \leq 2 \times 10^5$, $1 \leq a_i \leq 10^8$.