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].
import java.io.*;
import java.util.*;

public class Main
{
    static PrintWriter pw = new PrintWriter(System.out);

    static void add(int[] a , int x , int[] v)
    {
        v[x]++;
        
        if(a[0] == x || a[1] == x || a[2] == x)return;
            
        if(a[0] == Integer.MAX_VALUE)a[0] = x;
        else if(a[1] == Integer.MAX_VALUE)a[1] = x;
        else a[2] = x;
        Arrays.sort(a);
    }
    
    static void remove(int[] a , int x , int[] v)
    {
        v[x]--;
        if(v[x] == 0)
        {
            if(a[0] == x)a[0] = Integer.MAX_VALUE;
            else if(a[1] == x)a[1] = Integer.MAX_VALUE;
            else a[2] = Integer.MAX_VALUE;
        }
        
        Arrays.sort(a);
    }
    
    static boolean check(int[] a)
    {
        Arrays.sort(a);
        return a[2] == Integer.MAX_VALUE;
    }
   
    
    public static void main(String[] args)throws Exception
    {
        Reader.init(System.in);

        int n = Reader.nextInt();
        int[] ar = new int[n];
        int[] v = new int[(int)1e5 + 10];
        
        int[] a = new int[3];
        a[0] = a[1] = a[2] = Integer.MAX_VALUE;
        
        for(int i = 0 ; i<n ; i++)ar[i] = Reader.nextInt();
        
        int L = 0 , R = 0;
        
        int res = 0;
        while(R < n && L < n)
        {
            add(a , ar[R] , v );
            
            if(check(a))
            {
                res = Math.max(res, R - L + 1);
                R++;
            }
            else
            {
                while(!check(a) && L < n)
                {
                    remove(a , ar[L] , v);
                    L++;
                }
            
                res = Math.max(res, R - L + 1);
                R++;
            }
            
        }
        
        pw.println(res);
                
        pw.close();

    }


}



class Reader {

    static BufferedReader reader;
    static StringTokenizer tokenizer;

    public static int pars(String x) {
        int num = 0;
        int i = 0;
        if (x.charAt(0) == '-') {
            i = 1;
        }
        for (; i < x.length(); i++) {
            num = num * 10 + (x.charAt(i) - '0');
        }

        if (x.charAt(0) == '-') {
            return -num;
        }

        return num;
    }

    static void init(InputStream input) {
        reader = new BufferedReader(
                new InputStreamReader(input));
        tokenizer = new StringTokenizer("");
    }

    static void init(FileReader input) {
        reader = new BufferedReader(input);
        tokenizer = new StringTokenizer("");
    }

    static String next() throws IOException {
        while (!tokenizer.hasMoreTokens()) {
            tokenizer = new StringTokenizer(
                    reader.readLine());
        }
        return tokenizer.nextToken();
    }

    static int nextInt() throws IOException {
        return pars(next());
    }

    static long nextLong() throws IOException {
        return Long.parseLong(next());
    }

    static double nextDouble() throws IOException {
        return Double.parseDouble(next());
    }


}