题解 | #计算某字符出现次数#

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        String s = scanner.nextLine();
        HashSet<Character> set = new HashSet<>(s.length());
        for (int i = 0; i < s.length(); i++) {
            char cur = s.charAt(i);
            if (s.charAt(i) >= 0 && cur <= 127) 
                set.add(cur);
        }
        System.out.println(set.size());
    }
}