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].
#reader = open("input.txt", "r")
n = int(input())
x = input()
'''n = int(reader.readline())
x = reader.readline()'''
x = x.split(" ")
y = []
m = int(x[0])
M = int(x[0])
lastm = 0
lastM = 0

y.append(1)
for i in range(1, len(x)):
    x[i] = int(x[i])

    if x[i] == m + 1:
        #print("m+1", x[i], i)
        if m == M:
            M = m + 1
        y.append(y[i - 1] + 1)
        lastM = i
    elif x[i] == m:
        #print("m", x[i], i)
        lastm = i
        y.append(y[i - 1] + 1)
    elif x[i] == m - 1:
        if m == M:
            M = m
            m = M - 1
            lastM = lastm
            lastm = i
            y.append(y[i - 1] + 1)
        else:
            #print("Else", x[i], i)
            y.append(i - lastM)
            M = m
            lastM = lastm
            m = x[i]
            lastm = i
    elif x[i] == M + 1:
        #print("X", x[i],"lastm", lastm,"lastM", lastM)
        y.append(i - lastm)
        m = M
        lastm = lastM
        M = x[i]
        lastM = i
    else:
        m = x[i]
        M = m
        lastm = i
        lastM = i
        y.append(1)
#print()
yMax = 0
for number in y:
    #print(number)
    if number > yMax:
        yMax = number
print(yMax)



