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].
def maxConstant(N, array):
	max_ending_here = max_so_far = 1
	A = B = array[0]
	lastA = lastB = 0

	for x in range(1,N):
		if array[x] == array[x-1]:
			max_ending_here += 1
			if array[x] == A:
				lastA = x
			if array[x] == B:
				lastB = x
		elif A == B and abs(array[x] - A) == 1:
			max_ending_here += 1
			if array[x] > A:
				B = array[x]
				lastB = x
			else:
				A = array[x]
				lastA = x
		elif array[x] == A or array[x] == B:
			max_ending_here += 1
			if array[x] == B:
				lastB = x
			if array[x] == A:
				lastA = x
		elif array[x] > B:
			max_ending_here = x - lastA
			A = B
			lastA = x - 1
			B = array[x]
			lastB = x
		elif array[x] < A:
			max_ending_here = x - lastB
			B = A
			lastB = x - 1
			A = array[x]
			lastA = x
		max_so_far = max(max_so_far, max_ending_here)
	return max_so_far

if __name__=="__main__":
	N = int(input())
	array = input().split()
	array = [ int(x) for x in array ]
	print(maxConstant(N, array))