题解 | #HJ010 字符个数统计#

import java.util.*;

/**
 * HJ10 字符个数统计
 */
public class HJ010 {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        HashSet<Character> hs = new HashSet<>();
        for (int i = 0; i < str.length(); i++) {
            hs.add(str.charAt(i));
        }
        System.out.println(hs.size());
        sc.close();
    }

}