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 {
    private static final fast sc = new fast();
    private static final BufferedWriter sout = new BufferedWriter(new OutputStreamWriter(System.out));
    private static final int OO = (int) 1e9 + 1;
    private static final double PI = 3.141592653;
    private static final int[] dx4 = {0, 1, 0, -1}, dx = {0, 0, 1, -1, 1, -1, 1, -1};
    private static final int[] dy4 = {1, 0, -1, 0}, dy = {1, -1, 0, 0, 1, -1, -1, 1};
    //static void print6P{ System.out.printf("%8.6f\n"); }

    public static void main(String[] args) throws IOException {
        int n =sc.nextInt(),res =0;
        int [] arr =new int[n];
        Map<Integer,Integer>map =new HashMap<>();
        for(int i=0 ; i<n ;i++){
            int a =sc.nextInt();
            map.put(a,map.getOrDefault(a,0)+1);
            map.put(a+1,map.getOrDefault(a+1,0)+1);
            map.put(a-1,0);
            map.put(a+2,0);
            res = Math.max(res,Math.max(map.get(a),map.get(a+1)));
        }
        sout.write(res+"");
        sout.close();
    }
    
    static long gcd(long a, long b) {
      if (b == 0)
        return a;
      return gcd(b, a % b);
    }
    static class fast {
        BufferedReader br;
        StringTokenizer st;

        public fast() {
            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());
        }

        double nextFloat() {
            return Float.parseFloat(next());
        }

        String nextLine() {
            String str = "";
            try {
                str = br.readLine();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return str;
        }
    }
    static class Pair implements Comparable<Pair> {
        int first;
        int second;

        Pair(int first, int second) {
            this.first = first;
            this.second = second;
        }

        @Override
        public int compareTo(Pair o) {
            return Double.compare(o.first, first);
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) {
                return true;
            }
            if (!(o instanceof Pair)) {
                return false;
            }
            Pair pair = (Pair) o;
            if (first != pair.first) {
                return false;
            }
            return second == pair.second;
        }
    }
    static class Triple implements Comparable<Triple> {
        int first;
        int second;
        int third;

        Triple(int first, int second, int third) {
            this.first = first;
            this.second = second;
            this.third = third;
        }

        @Override
        public int compareTo(Triple o) {
            return Double.compare(o.first, first);
        }
    }
}
