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].
    /*
     * Code Author: Akshay Miterani
     * DA-IICT
     */
    import java.io.*;
import java.math.*;
import java.util.*;
     
     
    public class MainZ {
     
    	static double eps=(double)1e-6;;
    	static final int mod = (int) 1e9 + 7,block=300;
    	static final int MAX = 2 * (int) 1e5 + 10;
    	static int[] fact, factInv;
    	public static void main(String args[]){
    		InputReader in = new InputReader(System.in);
    		OutputStream outputStream = System.out;
    		PrintWriter out = new PrintWriter(outputStream);
    		//----------My Code Starts Here----------
    		int n=in.nextInt();
    		int a[]=new int[n];
    		for(int i=0;i<n;i++){
    			a[i]=in.nextInt();
    		}
    		int max=a[0];
    		int min=a[0];
    		int imax=0,imin=0;
    		long ans=Integer.MIN_VALUE;
    		int tmp=0;
    		for(int i=0;i<n;i++){
    			if(a[i]>=max){
    				max=a[i];
    				imax=i;
    			}
    			if(min>=a[i]){
    				min=a[i];
    				imin=i;
    			}
    			if(Math.abs(max-min)>1){
    				max=a[i-1];
    				min=a[i-1];
    				tmp=0;
    				i=Math.min(imax, imin);
    			}
    			else{
    				tmp++;
    				//System.out.println(tmp);
    				ans=Math.max(tmp, ans);
    			}
    		}
    		System.out.println(ans);
    		out.close();
    		//---------------The End------------------
    	}
    	
    	static class InputReader {
    	    public BufferedReader reader;
    	    public StringTokenizer tokenizer;
     
    	    public InputReader(InputStream inputstream) {
    	      reader = new BufferedReader(new InputStreamReader(inputstream));
    	      tokenizer = null;
    	    }
    	    
    	    public String nextLine(){
    	    	String fullLine=null;
    	    	while (tokenizer == null || !tokenizer.hasMoreTokens()) {
    	            try {
    	              fullLine=reader.readLine();
    	            } catch (IOException e) {
    	              throw new RuntimeException(e);
    	            }
    	            return fullLine;
    	          }
    	          return fullLine;
    	    }
    		public String next() {
    	      while (tokenizer == null || !tokenizer.hasMoreTokens()) {
    	        try {
    	          tokenizer = new StringTokenizer(reader.readLine());
    	        } catch (IOException e) {
    	          throw new RuntimeException(e);
    	        }
    	      }
    	      return tokenizer.nextToken();
    	    }
    		public long nextLong() {
    		      return Long.parseLong(next());
    		    }
    	    public int nextInt() {
    	      return Integer.parseInt(next());
    	    }
    	  }
    } 