using System;

public class Program

{

    public static void Main()

    {

        string userString = Console.ReadLine();

        int productOfNumbers = 1;

        for (int userStringIndex = 0; userStringIndex < userString.Length; userStringIndex++)

        {

            if (userString[userStringIndex] == ' ')

            {

                userStringIndex++;

            }

            else

            {

                productOfNumbers= productOfNumbers * Convert.ToInt32(userString[userStringIndex]);

            }

        }

        Console.WriteLine(productOfNumbers);

    }

}