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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.StringTokenizer;

public class CF602B {
    public static void main(String[] args) {
        FastReader input = new FastReader();
        PrintWriter pw = new PrintWriter(System.out);

        int n = input.nextInt();
        int[] arr = new int[n+1];

        for(int i = 1;i <= n;i++){
            arr[i] = input.nextInt();
        }

        int min = arr[1];
        int max = arr[1];

        int minIndex = 1;
        int maxIndex = 1;


        int frontPointer = 1;
        int backPointer = 1;

        int maxLen = 0;

        for(frontPointer = 1;frontPointer <= n;frontPointer++){
            if(arr[frontPointer] <= min){
                min = arr[frontPointer];
                minIndex = frontPointer;
            }
            if(arr[frontPointer] >= max){
                max = arr[frontPointer];
                maxIndex = frontPointer;
            }

            int diff = max - min;
            if(diff <= 1){
                maxLen = Math.max(maxLen,frontPointer - backPointer + 1);
            }
            else {
                if(arr[frontPointer] == min){
                    int val = arr[maxIndex];
                    while (arr[maxIndex] == val && maxIndex <= n){
                        maxIndex++;
                    }
                    backPointer = maxIndex;
                    max = arr[backPointer];
                }
                else if(arr[frontPointer] == max){
                    int val = arr[minIndex];
                    while (arr[minIndex] == val && minIndex <= n){
                        minIndex++;
                    }
                    backPointer = minIndex;
                    min = arr[backPointer];
                }
            }


        }

        pw.println(maxLen);


        // ****If sorting is required, use ArrayList
        pw.flush();
        pw.close();
    }
    static class FastReader
    {
        BufferedReader br;
        StringTokenizer st;

        public FastReader()
        {
            br = new BufferedReader(new
                    InputStreamReader(System.in));
        }

        String next()
        {
            while (st == null || !st.hasMoreElements())
            {
                try
                {
                    st = new StringTokenizer(br.readLine());
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
            return st.nextToken();
        }

        int nextInt()
        {
            return Integer.parseInt(next());
        }

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

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

        String nextLine()
        {
            String str = "";
            try
            {
                str = br.readLine();
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            return str;
        }
    }
}
