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 math;
from math import gcd,sqrt,floor,factorial,ceil
from bisect import bisect_left,bisect_right
import bisect;
import sys;
from sys import stdin,stdout
import os
sys.setrecursionlimit(pow(10,7))
import collections
from collections import defaultdict,Counter
from statistics import median
# input=stdin.readline
# print=stdout.write
from queue import Queue
inf = float("inf")
n=int(input())
l=list(map(int,input().split()))
def correct():
    if len(dict)>2:
        return 0;
    if len(dict)==1:
        return 1;
    l=list(dict)
    if abs(l[1]-l[0])<=1:
        return 1;
    return 0;
def reduce(a):
    dict[a]-=1
    if dict[a]==0:
        dict.pop(a)
it1=0;
it2=0;
dict=defaultdict(int)
maxa=0
while it1<n and it2<n:
    item2=l[it2]
    dict[item2]+=1
    if correct():
        length = it2 - it1 + 1
        if maxa<length:
            maxa=length
            # print(it1,it2)
        it2+=1

        continue
    while correct()==0 and it1<n:
        # dict[l[it1]]-=1;
        reduce(l[it1])
        it1+=1
    length = it2 - it1 + 1
    if maxa < length:
        maxa = length
        # print(it1, it2)
    it2 += 1
print(maxa)