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=int(input())
x=list(map(int,input().split()))
maxi,mini=x[0],x[0]
a,b=0,0
c=1
m=0
for i in range(1,n):
    if maxi==mini:
        if abs(maxi-x[i])==1:
            c+=1
            if x[i]>maxi:
                a=i
                b=-1
            else:
                b=i
                a=-1
            mini=min(mini,x[i])
            maxi=max(maxi,x[i])
        elif abs(maxi-x[i])==0:
            c+=1
        else:
            c=1
            maxi=mini=x[i]
            a=b=i
    elif x[i]==maxi:
        c+=1
        if a==-1:
            a=i
        b=-1
    elif x[i]==mini:
        c+=1
        if b==-1:
            b=i
        a=-1
    else:
        if x[i]==mini-1:
            if b==-1:
                c=1
                maxi=mini=x[i]
            else:
                c=i-b+1
                maxi=mini
                mini=x[i]
                a=-1
                b=i
        elif x[i]==maxi+1:
            if a==-1:
                c=1
                maxi=mini=x[i]
            else:
                c=i-a+1
                mini=maxi
                maxi=x[i]
                b=-1
                a=i
    m=max(m,c)
print(m)