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.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.io.BufferedWriter;
import java.io.Writer;
import java.io.OutputStreamWriter;
import java.util.InputMismatchException;
import java.io.IOException;
import java.util.LinkedList;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        InputReader in = new InputReader(inputStream);
        OutputWriter out = new OutputWriter(outputStream);
        BApproximatingAConstantRange solver = new BApproximatingAConstantRange();
        solver.solve(1, in, out);
        out.close();
    }

    static class BApproximatingAConstantRange {
        public void solve(int testNumber, InputReader in, OutputWriter out) {
            int n = in.nextInt();
            LinkedList<int[]> minQ = new LinkedList<>();
            LinkedList<int[]> maxQ = new LinkedList<>();
            int start = 0;
            int min = -100;
            int max = 1000_100;
            int maxLen = 0;
            for (int i = 0; i < n; i++) {
                int num = in.nextInt();
                while (minQ.size() > 0 && minQ.getLast()[0] >= num) {
                    minQ.removeLast();
                }
                while (maxQ.size() > 0 && maxQ.getLast()[0] <= num) {
                    maxQ.removeLast();
                }
                maxQ.add(new int[]{num, i});
                minQ.add(new int[]{num, i});
                if (Math.abs(num - min) > 1) {
                    while (minQ.getFirst()[0] == min) {
                        start = minQ.getFirst()[1] + 1;
                        minQ.removeFirst();
                    }
                }
                if (Math.abs(num - max) > 1) {
                    while (maxQ.getFirst()[0] == max) {
                        start = maxQ.getFirst()[1] + 1;
                        maxQ.removeFirst();
                    }
                }
                while (maxQ.size() > 0 && maxQ.getFirst()[1] < start) {
                    maxQ.removeFirst();
                }
                while (minQ.size() > 0 && minQ.getFirst()[1] < start) {
                    minQ.removeFirst();
                }
                max = maxQ.getFirst()[0];
                min = minQ.getFirst()[0];
                maxLen = Math.max(maxLen, i - start + 1);
            }
            out.println(maxLen);
        }

    }

    static class OutputWriter {
        private final PrintWriter writer;

        public OutputWriter(OutputStream outputStream) {
            writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(outputStream)));
        }

        public OutputWriter(Writer writer) {
            this.writer = new PrintWriter(writer);
        }

        public void close() {
            writer.close();
        }

        public void println(int i) {
            writer.println(i);
        }

    }

    static class InputReader {
        final private int BUFFER_SIZE = 1 << 16;
        private InputStream stream;
        private byte[] buf = new byte[BUFFER_SIZE];
        private int curChar;
        private int numChars;
        private InputReader.SpaceCharFilter filter;

        public InputReader(InputStream stream) {
            this.stream = stream;
        }

        public int read() {
            if (numChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= numChars) {
                curChar = 0;
                try {
                    numChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (numChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public int nextInt() {
            int c = read();
            while (isSpaceChar(c)) {
                c = read();
            }
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = read();
            }
            int res = 0;
            do {
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = read();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        public boolean isSpaceChar(int c) {
            if (filter != null) {
                return filter.isSpaceChar(c);
            }
            return isWhitespace(c);
        }

        public static boolean isWhitespace(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

        public interface SpaceCharFilter {
            public boolean isSpaceChar(int ch);

        }

    }
}

