import java.io.*;
import java.util.*;
import java.awt.geom.*;

/**
 * Solution to Simplicity
 * 
 * @author vanb
 */
public class simplicity_vanb
{
    public Scanner sc;
    public PrintStream ps;
        
    /**
     * Driver.
     * @throws Exception
     */
    public void doit() throws Exception
    {
        sc = new Scanner( System.in );
        ps = System.out;;

        char letters[] = sc.next().trim().toCharArray();
        int counts[] = new int[26];
        Arrays.fill( counts, 0 );
        
        // Count the occurrences of each letter,
        // mapping a to 0, b to 1, ..., y to 24, z to 25
        for( char letter : letters )
        {
            ++counts[(int)(letter-'a')];
        }
        
        // Sort'em!
        Arrays.sort( counts );
        int sum = 0;
        
        // The answer is the sum of all but the two biggest.
        // So, we'll add up 0..23, and skip 24 and 25
        for( int i=0; i<24; i++ )
        {
            sum += counts[i];
        }
        
        ps.println( sum );
    }
    
    /**
     * @param args
     */
    public static void main( String[] args ) throws Exception
    {
        new simplicity_vanb().doit();        
    }   
}