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 a1, ..., an. There aren't any big jumps between consecutive data points — for each 1 ≤ i < n, it's guaranteed that |ai + 1 - ai| ≤ 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 ai 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 a1, a2, ..., an (1 ≤ ai ≤ 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].
import sys
import string
import math
from collections import defaultdict
from functools import lru_cache
from collections import Counter

def mi(s):
    return map(int, s.strip().split())

def lmi(s):
    return list(mi(s))

def tmi(s):
    return tuple(mi(s))

def mf(f, s):
    return map(f, s)

def lmf(f, s):
    return list(mf(f, s))

def js(lst):
    return " ".join(str(d) for d in lst)

def line():
    return sys.stdin.readline().strip()

def linesp():
    return line().split()

def iline():
    return int(line())

def mat(n):
    matr = []
    for _ in range(n):
        matr.append(linesp())
    return matr

def mati(n):
    mat = []
    for _ in range(n):
       mat.append(lmi(line())) 
    return mat

def dist(x, y):
    return ((x[0] - y[0])**2 + (x[1] - y[1])**2)**0.5

def main(arr):
    m_g = {}
    m_l = {}
    m_g[0] = 1
    m_l[0] = 1

    longest = 1
    for i in range(1, len(arr)):
        if arr[i - 1] == arr[i]:
            m_g[i] = m_g[i - 1] + 1
            m_l[i] = m_l[i - 1] + 1
        elif arr[i - 1] > arr[i]:
            m_g[i] = m_l[i - 1] + 1
            m_l[i] = 1
        elif arr[i - 1] < arr[i]:
            m_l[i] = m_g[i - 1] + 1
            m_g[i] = 1

        longest = max([longest, m_l[i], m_g[i]])
    print(longest)

if __name__ == "__main__":
    line()
    arr = lmi(line())
    main(arr)
