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].
//package codeforces;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

/**
 * @author muhossain
 * @since 2020-07-14
 */

public class B602 {
    public static void main(String[] args) {
        FastScanner fs = new FastScanner(System.in);
        int n = fs.nextInt();

        int[] data = new int[n];

        for (int i = 0; i < n; i++) {
            data[i] = fs.nextInt();
        }

        int i = 1;
        int leftMin, leftMax;

        leftMin = data[0];
        leftMax = data[0];
        int leftPointer = 0;

        int maxDistance = 0;

        while (i < n) {
            if (Math.abs(leftMax - data[i]) >= 2 || Math.abs(leftMin - data[i]) >= 2) {
                leftPointer = i;

                leftMin = data[i];
                leftMax = data[i];

                while (Math.abs(leftMax - data[leftPointer]) < 2 && Math.abs(leftMin - data[leftPointer]) < 2) {
                    leftMin = Math.min(leftMin, data[leftPointer]);
                    leftMax = Math.max(leftMax, data[leftPointer]);

                    leftPointer--;
                }

                leftPointer++;

            } else {
                leftMin = Math.min(leftMin, data[i]);
                leftMax = Math.max(leftMax, data[i]);

                maxDistance = Math.max(maxDistance, i - leftPointer + 1);
            }

            i++;
        }

        System.out.println(maxDistance);
    }

    static class FastScanner {
        private BufferedReader reader = null;
        private StringTokenizer tokenizer = null;

        public FastScanner(InputStream in) {
            reader = new BufferedReader(new InputStreamReader(in));
            tokenizer = null;
        }

        public String next() {
            if (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    tokenizer = new StringTokenizer(reader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }
            return tokenizer.nextToken();
        }

        public String nextLine() {
            if (tokenizer == null || !tokenizer.hasMoreTokens()) {
                try {
                    return reader.readLine();
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }

            return tokenizer.nextToken("\n");
        }

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

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

