// 2023 IUSB Programming Competition
// Round 1 Problem 6
// Alphabetical Order
// Solution by Liguo Yu

import java.util.Scanner;

public class round1_p6
{   
    public static void main(String[] args)
    {
        Scanner input = new Scanner(System.in);
	    String user_input = input.nextLine();
        char[] letters = new char[10];
        
        for(int i=0; i<10; i++)
        {
            letters[i] =user_input.charAt(i);
        }
        
        int longest = longestOrder(letters, 10);
        
        System.out.println(10-longest);
    }
    
    static int longestOrder(char array[], int n)
    {
        int list[] = new int[n]; // store the longest increasing oder starting from evey index
        
 
        for (int i = 0; i < n; i++)
        {
            list[i] = 1; // initialize to 1
        }
 
        for (int i = 1; i < n; i++)
        {
            for (int j = 0; j < i; j++)
            {
                // update longest increasing order from position j by comparing its value with 
                // values ahead of it and their longest increasing order 
                if (array[i] > array[j] && list[i] < list[j] + 1)
                {
                    list[i] = list[j] + 1;
                }
            }
        }
  
        int max = 1; // find the the longest longest increasing oder starting from all indecies
        for (int i = 0; i < n; i++)
        {
            if (max < list[i])
                max = list[i];
        }
 
        return max;
    }
}