using System;

using System.Linq;

​

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Please enter comma-separated values.");

        string input = Console.ReadLine();

        string[] values = input.Split(',');

        values = values.Select(v => v.Replace(" ", "")).ToArray();

        int[] values_int = values.Select<string, int>(v =>

        {

            int output;

            if (!Int32.TryParse(v, out output))

            {

                return 0;

            }

​

            return output;

        }).ToArray();

        Console.WriteLine(values_int.Max());

    }

}