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.util.*;
import java.io.*;
import static java.lang.Math.*;

public class Test {
    FastIO sc;
    int n;
    int[] dp;
    int M = 1000000007;

    void solve() throws Exception {
        int n = sc.nextInt();
        int[] a = new int[n];
        for (int i = 0; i < a.length; i++) {
            a[i] = sc.nextInt();
            // a[i] = 100000;
        }
        HashSet<Integer> set = new HashSet<>();
        int l = 0, r = 0, max = Integer.MIN_VALUE, c = 0;
        int prev = a[0], id = l;
        while (l < a.length && r < a.length) {
            // System.out.println(l+" "+r);
            set.add(a[r]);
            // System.out.println(id);

            if (set.size() > 2) {
                l = id;
                r = l;
                max = max(max, c);
                c = 0;
                set.clear();
                prev = a[l];
                id = 0;
            } else {
                if (prev != a[r]) {
                    id = r;
                    prev = a[r];
                }
                c = r - l + 1;

                r++;

            }

        }
        System.out.println(max(max, c));
    }

    void run() {
        try {
            sc = new FastIO();
            solve();
            sc.close();
        } catch (Exception e) {
            e.printStackTrace();
            System.exit(abs(-1));
        }
    }

    public static void main(String[] args) {
        try {
            Locale.setDefault(Locale.US);
        } catch (Exception ignore) {
        }
        new Test().run();
    }

    class FastIO extends PrintWriter {
        private BufferedReader in;
        private StringTokenizer stok;

        FastIO() {
            super(System.out);
            in = new BufferedReader(new InputStreamReader(System.in));
        }

        FastIO(String s) throws FileNotFoundException {
            super("".equals(s) ? "output.txt" : s + ".out");
            in = new BufferedReader(new FileReader("".equals(s) ? "input.txt" : s + ".in"));
        }

        @Override
        public void close() {
            super.close();
            try {
                in.close();
            } catch (IOException ignored) {
            }
        }

        String next() {
            while (stok == null || !stok.hasMoreTokens()) {
                try {
                    stok = new StringTokenizer(in.readLine());
                } catch (Exception e) {
                    return null;
                }
            }
            return stok.nextToken();
        }

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

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

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

        String nextLine() {
            try {
                return in.readLine();
            } catch (IOException e) {
                return null;
            }
        }

        char[] nextCharArray() {
            return next().toCharArray();
        }
    }

    class Pair {
        int mon, fac;

        Pair(int mon, int fac) {
            this.mon = mon;
            this.fac = fac;
        }
    }

    void randomShuffle(int[] a) {
        Random random = new Random();
        for (int i = 1; i < a.length; i++) {
            int x = random.nextInt(i + 1);
            int xchg = a[i];
            a[i] = a[x];
            a[x] = xchg;
        }
    }

    static boolean even(int n) {
        int r = n & 1;
        return r != 1 ? true : false;
    }
}