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].
from collections import deque

def max_range(l):
    max_deque = deque()
    min_deque = deque()
    idx = 0
    maxlen = 0


    for i in xrange(len(l)):
        current = l[i]
        while len(max_deque) > 0 and current >= max_deque[-1][0]:
            max_deque.pop()
        while len(min_deque) > 0 and current <= min_deque[-1][0]:
            min_deque.pop()
        max_deque.append((current, i))
        min_deque.append((current, i))

        while len(min_deque) > 0 and  abs(current - min_deque[0][0]) > 1:
            a = min_deque.popleft()
            idx = a[1] + 1

        while len(max_deque) > 0 and abs(max_deque[0][0] - current) > 1:
            b = max_deque.popleft()
            idx = b[1] + 1 if b[1] + 1 > idx else idx

        maxlen = max([i - idx + 1, maxlen])

    return maxlen


def test():
    l = [1, 2, 3, 3, 2]
    print(max_range(l))


def test2():
    l = [5, 4, 5, 5, 6, 7, 8, 8, 8, 7, 6]
    print(max_range(l))


def main():
    n = int(raw_input())
    l = [int(_) for _ in raw_input().split(' ')]

    print(max_range(l))


if __name__=='__main__':
    main()

