字符个数统计

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

public class Main {

    public Main() {

        Scanner in = new Scanner(System.in);
        String input = in.next();
        Set<Character> set = new HashSet<>();
        for (char ch : input.toCharArray()) {
            if (ch >= 0 && ch < 128) {
                set.add(ch);
            }
        }
        System.out.println(set.size());
    }

    public static void main(String[] args) {
        Main solution = new Main();
    }
}