When Xellos was doing a practice course in university, he once had to measure the intensity of an effect that slowly approached equilibrium. A good way to determine the equilibrium intensity would be choosing a sufficiently large number of consecutive data points that seems as constant as possible and taking their average. Of course, with the usual sizes of data, it's nothing challenging — but why not make a similar programming contest problem while we're at it?

You're given a sequence of $*n*$ data points $*a*_{1}, ..., *a*_{*n*}$. There aren't any big jumps between consecutive data points — for each $1 ≤ *i* < *n*$, it's guaranteed that $|*a*_{*i* + 1} - *a*_{*i*}| ≤ 1$.

A range $[*l*, *r*]$ of data points is said to be almost constant if the difference between the largest and the smallest value in that range is at most $1$. Formally, let $*M*$ be the maximum and $*m*$ the minimum value of $*a*_{*i*}$ for $*l* ≤ *i* ≤ *r*$; the range $[*l*, *r*]$ is almost constant if $*M* - *m* ≤ 1$.

Find the length of the longest almost constant range.

Input

The first line of the input contains a single integer $*n*$ ($2 ≤ *n* ≤ 100 000$) — the number of data points.

The second line contains $*n*$ integers $*a*_{1}, *a*_{2}, ..., *a*_{*n*}$ ($1 ≤ *a*_{*i*} ≤ 100 000$).

Output

Print a single number — the maximum length of an almost constant range of the given sequence.

Note

In the first sample, the longest almost constant range is $[2, 5]$; its length (the number of data points in it) is 4.

In the second sample, there are three almost constant ranges of length $4$: $[1, 4]$, $[6, 9]$ and $[7, 10]$; the only almost constant range of the maximum length $5$ is $[6, 10]$.