Problem Statement

You are given an integer sequence of length $N$, $a_1,a_2,...,a_N$.

For each $1≤i≤N$, you have three choices: add $1$ to $a_i$, subtract $1$ from $a_i$ or do nothing.

After these operations, you select an integer $X$ and count the number of $i$ such that $a_i=X$.

Maximize this count by making optimal choices.

Constraints

• $1≤N≤10^5$
• $0≤a_i<10^5 (1≤i≤N)$
• $a_i$ is an integer.

Input

The input is given from Standard Input in the following format:

N
a_1 a_2 .. a_N

Output

Print the maximum possible number of $i$ such that $a_i=X$.