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].
n = input()
a = [int(x) for x in raw_input().strip().split()]
d = {}
overall_longest = 1
longest, longest_min, longest_max = 1, a[0], a[0]
last_num, init_occur = a[0], 0
# print overall_longest, longest, longest_min, longest_max, a[0]
for i in range(1,n):
	if a[i-1] != last_num:
		last_num, init_occur = a[i-1], i-1
	if longest_min == longest_max:
		if abs(a[i] - longest_min) <= 1:
			longest_min = min(a[i], longest_min)
			longest_max = max(a[i], longest_max)
			longest += 1
		else:
			longest, longest_min, longest_max = 1, a[i], a[i]
	else:
		if abs(a[i] - longest_min) <= 1 and abs(a[i] - longest_max) <= 1:
			longest_min = min(a[i], longest_min)
			longest_max = max(a[i], longest_max)
			longest += 1
		else:
			if abs(a[i] - longest_min) <= 1:
				longest_max = longest_min
				longest_min = int(a[i])
				longest = i-init_occur+1
			elif abs(a[i] - longest_max) <= 1:
				longest_min, longest_max = longest_max, a[i]
				longest = i-init_occur+1
			else:
				longest, longest_min, longest_max = 1, a[i], a[i]
	overall_longest = max(overall_longest, longest)
	# print overall_longest, longest, longest_min, longest_max, a[i]

print overall_longest
