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.BufferedWriter;
import java.io.ByteArrayInputStream;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;

public class Main {
    private static final long MOD = (long) 1e9 + 7;
    static InputStream is;
    static PrintWriter out;
    static String INPUT = "";
    static int lenbuf = 0, ptrbuf = 0;
    private static byte[] inbuf = new byte[1024];
    static boolean readFile = false; //set to true if the questions require file I/O

    static void solve() {
        int n = ni();
        int[] dp = new int[1000001];
        int res = 1, l = 0;
        for (int i = 1; i <= n; i++) {
            int a = ni();
            a++;
            l = Math.max(l, dp[a - 2]);
            l = Math.max(l, dp[a + 2]);
            dp[a] = i;
            res = Math.max(res, i - l);
        }
        out.println(res);

    }

    static void execute() throws IOException {
            solve();
    }

    public static void main(String[] args) throws Exception {
        long S = System.currentTimeMillis();
        if (readFile) {
            is = new FileInputStream("input.txt");
            out = new PrintWriter(new BufferedWriter(new FileWriter("output.txt")));
        } else {
            is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
            out = new PrintWriter(System.out);
        }

        execute();
        out.flush();
        long G = System.currentTimeMillis();
        tr(G - S + "ms");
    }

    private static int upperBound(int[] a, int l, int r, int target) {
        while (l < r) {
            int mid = l + (r - l) / 2;
            if (a[mid] > target) {
                r = mid;
            } else {
                l = mid + 1;
            }
        }
        return l;
    }

    private static boolean eof() {
        if (lenbuf == -1) {
            return true;
        }
        int lptr = ptrbuf;
        while (lptr < lenbuf) {
            if (!isSpaceChar(inbuf[lptr++])) {
                return false;
            }
        }

        try {
            is.mark(1000);
            while (true) {
                int b = is.read();
                if (b == -1) {
                    is.reset();
                    return true;
                } else if (!isSpaceChar(b)) {
                    is.reset();
                    return false;
                }
            }
        } catch (IOException e) {
            return true;
        }
    }

    private static int readByte() {
        if (lenbuf == -1) {
            throw new InputMismatchException();
        }
        if (ptrbuf >= lenbuf) {
            ptrbuf = 0;
            try {
                lenbuf = is.read(inbuf);
            } catch (IOException e) {
                throw new InputMismatchException();
            }
            if (lenbuf <= 0) {
                return -1;
            }
        }
        return inbuf[ptrbuf++];
    }

    private static boolean isSpaceChar(int c) {
        return !(c >= 33 && c <= 126);
    }

    //	private static boolean isSpaceChar(int c) { return !(c >= 32 && c <= 126); }
    private static int skip() {
        int b;
        while ((b = readByte()) != -1 && isSpaceChar(b)) {
            ;
        }
        return b;
    }

    private static double nd() {
        return Double.parseDouble(ns());
    }

    private static char nc() {
        return (char) skip();
    }

    private static String ns() {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while (!(isSpaceChar(b))) {
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }

    private static char[] ns(int n) {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while (p < n && !(isSpaceChar(b))) {
            buf[p++] = (char) b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }

    private static char[][] nm(int n, int m) {
        char[][] map = new char[n][];
        for (int i = 0; i < n; i++) {
            map[i] = ns(m);
        }
        return map;
    }

    private static int[] na(int n) {
        int[] a = new int[n];
        for (int i = 0; i < n; i++) {
            a[i] = ni();
        }
        return a;
    }

    private static int ni() {
        int num = 0, b;
        boolean minus = false;
        while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')) {
            ;
        }
        if (b == '-') {
            minus = true;
            b = readByte();
        }

        while (true) {
            if (b >= '0' && b <= '9') {
                num = num * 10 + (b - '0');
            } else {
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private static long nl() {
        long num = 0;
        int b;
        boolean minus = false;
        while ((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-')) {
            ;
        }
        if (b == '-') {
            minus = true;
            b = readByte();
        }

        while (true) {
            if (b >= '0' && b <= '9') {
                num = num * 10 + (b - '0');
            } else {
                return minus ? -num : num;
            }
            b = readByte();
        }
    }

    private static void tr(Object... o) {
        if (INPUT.length() != 0) {
            System.out.println(Arrays.deepToString(o));
        }
    }
}
