Longest Consecutive Subarray

Given an array of integers, find the length of the longest subarray that can be rearranged to form a consecutive sequence.

A consecutive sequence is defined as a sequence of integers that can be arranged in the form:

$$a, a+1, a+2, \dots, a+k$$

where each element after rearrangement differs by 1 from its adjacent element. Note that duplicates in the input array are considered only once.

For example, for the array [1, 2, 2, 3, 4, 5], the longest subarray which can be rearranged to form a consecutive sequence is [1, 2, 3, 4, 5] with a length of 5.

inputFormat

The input is given via standard input. The first line contains an integer N, representing the number of elements in the array. The second line contains N space-separated integers.

If N is 0, the array is empty.

outputFormat

Output a single integer which is the length of the longest subarray that can be rearranged to form a consecutive sequence.

## sample

6
1 2 2 3 4 5

5