Java 代码

import java.util.Scanner;

public class Main
{
    public static void main (String[] args)
    {
        Scanner cin = new Scanner(System.in);

        String s = cin.nextLine();

        int count = 0;
        for (int i = 0; i < s.length(); i ++)
        {
            if (s.charAt(i) >= '0' && s.charAt(i) <= '9')
                count += 1;
        }

        System.out.println (count);
    }
}