using System;

public class Program

{

    public static void Main()

    {

    int n, tong,i;

    Console.Write("Nhap n: ");

    n = int.Parse(Console.ReadLine());

    tong = 0;

    while (n!=0)

        {

        i = n%10;

        if (i%2==0) tong = tong+i;

        n=n/10;

        }

    Console.Write("Tong chu so chan la {0}",tong);

    }

}