// Arup Guha
// 11/14/2015
// Solution to 2015 SER D1/D2 Problem: Simplicity

import java.util.*;

public class simplicity {

	public static void main(String[] args) {

		// Read input.
		Scanner stdin = new Scanner(System.in);
		String s = stdin.next();

		// Get frequency count, and sort.
		int[] freq = new int[26];
		for (int i=0; i<s.length(); i++)
			freq[s.charAt(i)-'a']++;
		Arrays.sort(freq);

		// Add up frequencies of all letters but last two and print.
		int res = 0, index = 0;
		for (int i=0; i<24; i++)
			res += freq[i];
		System.out.println(res);
	}
}