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].
'''input
11
5 4 5 5 6 7 8 8 8 7 6
'''
#602/b

n = int(input())
arr = tuple(map(int,input().split()))
l = 0
lastedgelocation = 0
lastedge = 0
maxx = -1
for i in range(1,n):
	temp = arr[i]-arr[i-1]
	if temp:
		if temp==lastedge:
			l = lastedgelocation
		lastedge = temp
		lastedgelocation = i
	maxx = max(maxx,i-l+1)
print(maxx)
quit()
#1189/c
n = int(input())
a = tuple(map(int,input().split()))
block_size = int(pow(n,0.5))
b = [0 for i in range(n//block_size+2)]
for i in range(0,n,block_size):
	b[i//block_size] = sum(a[i:i+block_size])
q = int(input())
for _ in range(q):
	l,r = map(lambda x:int(x)-1,input().split())
	l1,l2 = l//block_size ,r//block_size
	s = sum(b[l1:l2]) - sum(a[l1*block_size:l]) + sum(a[l2*block_size:r+1])
	print(s//10)