No tag edit access

B. Approximating a Constant Range

time limit per test

2 secondsmemory limit per test

256 megabytesinput

standard inputoutput

standard outputWhen 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.

Examples

Input

5

1 2 3 3 2

Output

4

Input

11

5 4 5 5 6 7 8 8 8 7 6

Output

5

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].

Codeforces (c) Copyright 2010-2017 Mike Mirzayanov

The only programming contests Web 2.0 platform

Server time: Jun/24/2017 16:44:46 (c4).

Desktop version, switch to mobile version.

User lists

Name |
---|