ProgMasters 16 - Mirror

16 - Mirror

Test
We'll say that a "mirror" section in an array is a group of contiguous elements, such that somewhere in the array, the same group appears in reverse order. For example, the largest mirror section in {1, 2, 3, 8, 9, 3, 2, 1} is length 3 (the {1, 2, 3} part), or in {1, 2, 1, 3} it's 3 as well (the {1, 2, 1} part). Return the size of the largest mirror section found in the given array.

HINT: There might be negative numbers as well!

Input Format
The first line contains a single integer, n, denoting the size of the array. Each of the subsequent n lines contains a single integer denoting the value of the array at the next position.

Output Format
A number.


Sample input
7
7
1
2
9
7
2
1

Sample output
2