Longest Consecutive Subsequence

Given an integer array, your task is to find the length of the longest consecutive subsequence in the array. A consecutive subsequence is a sequence of numbers where each number is exactly one greater than the previous number. For instance, in the array [100, 4, 200, 1, 3, 2, 5], the longest consecutive subsequence is [1, 2, 3, 4, 5] which has a length of 5.

You can use the following mathematical formulation: if a subsequence is given by \(a_1, a_2, \dots, a_k\), then it must satisfy \(a_i = a_1 + (i - 1)\) for \(i = 1, 2, \dots, k\).

Your solution must read input from standard input and print the answer to standard output.

inputFormat

The first line contains a single integer \(n\) representing the number of elements in the array. The second line contains \(n\) space-separated integers which constitute the array.

outputFormat

Output a single integer representing the length of the longest consecutive subsequence in the array.

7
100 4 200 1 3 2 5

5