using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Test".Substring(0, 1));

        Console.WriteLine("{0}", LCP("apple", "applesauce"));

    }

    public static int LCP(string s1, string s2)

    {

        if (s1.Substring(0, 1) == s2.Substring(0, 1)) return 1 + LCP(s1.Remove(0, 1), s2.Remove(0, 1));

        return 0;

    }

}