Longest Consecutive Increasing Subsequence

You are given a sequence of integers. Your task is to find the length of the longest contiguous subsequence such that each element in the subsequence is exactly 1 greater than its previous element.

For example, given the sequence:

1 2 3 5 6 7 8

There are two increasing segments: 1 2 3 and 5 6 7 8. The second segment has a length of 4, which is the answer.

Note: The subsequence must consist of adjacent elements in the original sequence.

inputFormat

The first line contains a single integer n, representing the number of elements in the sequence. The second line contains n space-separated integers.

outputFormat

Output a single integer, the length of the longest contiguous subsequence where each element is exactly one greater than the previous element.## sample

7
1 2 3 5 6 7 8

4