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.HashMap;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.InputStream;
/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 * @author Alex
 */
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);
		TaskB solver = new TaskB();
		solver.solve(1, in, out);
		out.close();
	}
	static class TaskB{
		public void solve(int testNumber, InputReader in, OutputWriter out){
			int n = in.ri();
			int[] a = IOUtils.readIntArray(in, n);
			HashMap<Integer, Integer> count = new HashMap<>();
			int res = 0, left = 0;
			for(int i = 0; i < n; i++) {
				int val = a[i];
				count.merge(val, 1, Integer::sum);
				while(true){
					int want = i - left + 1;
					int same = count.containsKey(val) ? count.get(val) : 0;
					int less = count.containsKey(val - 1) ? count.get(val - 1) : 0;
					int more = count.containsKey(val + 1) ? count.get(val + 1) : 0;
					if(same + less == want || same + more == want) break;
					count.merge(a[left], -1, Integer::sum);
					left++;
				}
				res = Math.max(res, i - left + 1);
			}
			out.printLine(res);
		}
	}
	static class IOUtils{
		public static int[] readIntArray(InputReader in, int size){
			int[] array = new int[size];
			for(int i = 0; i < size; i++)
				array[i] = in.readInt();
			return array;
		}
	}
	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 printLine(int i){
			writer.println(i);
		}
	}
	static class InputReader{
		private InputStream stream;
		private byte[] buf = new byte[1024];
		private int curChar;
		private int numChars;
		private 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 ri(){
			return readInt();
		}
		public int readInt(){
			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);
		}
	}
}

