题解 | #字符个数统计#

import java.util.Scanner;
import java.util.HashSet;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        HashSet<Character> set = new HashSet<>();
        while (in.hasNext()) { 
            String a = in.next();
            for(int i=0;i<a.length();i++){
                if(a.charAt((i))>=0 && a.charAt((i))<=127){
                    set.add(a.charAt(i));
                }
            }
            System.out.println(set.size());
        }
    }
}