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.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintStream;
import java.util.HashMap;
import java.util.Map;
import java.util.StringTokenizer;

public class ProbE {
    public static void main(String[] args) throws Exception {
        new ProbE().solve(System.in, System.out);
    }

    private void solve(InputStream is, OutputStream os) {
        PrintStream ps = new PrintStream(System.out);
        CustomScanner cs = new CustomScanner(System.in);
        // Write your code here
        int n = cs.nextInt();
        int[] a = new int[100001];
        int index = 0;
        while (index < n) {
            a[index] = cs.nextInt();
            index++;
        }
        int maxLen = 0;
        int tempLen = 0;
        int i = 0;
        int j = 0;
        Map<Integer, Integer> maxSet = new HashMap<>();
        while (i < n) {
            while (j < n) {
                maxSet.put(a[j],
                        maxSet.get(a[j]) == null ? 1 : maxSet.get(a[j]) + 1);
                if (maxSet.size() > 2) {
                    break;
                } else {
                    j++;
                    tempLen++;
                }
            }
            if (tempLen > maxLen) {
                maxLen = tempLen;
            }
            if (j == n) {
                break;
            } else {
                int diff = 0;
                while (i < j) {
                    diff = Math.abs(a[j] - a[i]);
                    if (diff > 1 || maxSet.size() > 2) {
                        if (maxSet.get(a[i]) != null) {
                            maxSet.put(a[i], maxSet.get(a[i]) - 1);
                        }
                        if (maxSet.get(a[i]) != null && maxSet.get(a[i]) == 0) {
                            maxSet.remove(a[i]);
                        }
                        i++;
                    } else {
                        tempLen = j - i + 1;
                        j++;
                        break;
                    }
                }
            }
        }
        ps.println(maxLen);
        ps.close();
        cs.close();
    }

    public class CustomScanner {
        private BufferedReader br;
        private StringTokenizer st;

        public CustomScanner(InputStream in) {
            this.br = new BufferedReader(new InputStreamReader(System.in));
        }

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

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

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

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

        public void close() {
            try {
                br.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

}