Given a list of integers, find the length of the longest range of consecutive integers that are contained in the sorted version of the list.

Here's an illustrative example. Consider the list:

[4, 9, 10, 5, 17, 3, 8, 11, 1, 12, 18, 20]

... which, after sorting, becomes:

[1, 3, 4, 5, 8, 9, 10, 11, 12, 17, 18, 20]

The longest consecutive subsequence is now clearly [8, 9, 10, 11, 12], which has length 5.

Examples

max_consec([4, 9, 10, 5, 17, 3, 8, 11, 1, 12, 18, 20]) ➞ 5
# After sorting list becomes [1, 2, 4, 5, 8, 9, 10, 11, 12, 17, 18, 20]
# Longest consecutive subsequence is [8, 9, 10, 11, 12], which has length 5

max_consec([14, 13, 7, 1, 4, 12, 3, 7, 7, 12, 11, 5, 7]) ➞ 4
# After sorting get [1, 3, 4, 5, 7, 7, 7, 7, 11, 12, 12, 13, 14]
# Longest consecutive subsequence is [11, 12, 13, 14], which has length 4

max_consec([13, 3, 8, 5, 5, 2, 13, 6, 14, 2, 11, 4, 10, 8, 1, 9]) ➞ 6
# After sorting get [1, 2, 2, 3, 4, 5, 5, 6, 8, 8, 9, 10, 11, 13, 13, 14]
# Longest consecutive subsequence is [1, 2, 3, 4, 5, 6], which has length 6

Notes

As in the 2nd and 3rd examples, the given list is allowed to include repeated elements, but such repetitions are ignored when finding the longest range of consecutive elements.