namespace fivaldi
{
    public static class Util
    {
        public static string ConvertPIN(string birthDay)
        {
            if (string.IsNullOrEmpty(birthDay))
            {
                return string.Empty;
            }
            if (birthDay.Length < 10)
            {
                return string.Empty;
            }
            return birthDay.Substring(0, 2) + birthDay.Substring(3, 2) + birthDay.Substring(8, 2);
        }
    }
}