/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		String s ="abaaabcadabcbcaa";
		int k=2;
		int res = maximumLengthOfString(s,k);	
		System.out.println(res);
	}
	
	public static int maximumLengthOfString(String s,int k){
		int n = s.length();
		int dp[] = new int[n];
		dp[0] = 1;
		for(int i=1;i<n;i++){
			dp[i] = Math.abs(s.charAt(i) - s.charAt(i-1)) <=2 ? dp[i-1]+1 : 1;
		}
		int max =0;
		for(int i=0;i<n;i++){
			max = Math.max(dp[i],max);
		}
		
		return max;
	}
 
}