18:字符个数统计

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        String input = in.nextLine();
        int[] nums = new int[128];
        int length = 0;
        for(int i = 0;i<input.length();i++)
        {
            nums[input.charAt(i)] = 1;
        }
        for(int j = 0;j<nums.length;j++)
        {
            if(nums[j] == 1 ){
                length++;
            }
        }
        System.out.println(length);
    }

}