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

#include <iostream>

using namespace std;
int longestOrder(char * array, int n);

int main()
{
  char * letters = new char[10];
	
	for(int i = 0; i < 10; i++)
  {
    cin >> letters[i];
  }
    
  int longest = longestOrder(letters, 10);
        
  cout << 10-longest;
  return 0;
}

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;
}