class Program
    {
        public enum Month
        {
            jan = 1, 
            feb = 2,
            mar = 3, 
            apr = 4,
            may = 5,
            jun = 6, 
            jul = 7, 
            aug = 8,
            sep = 8,
            oct = 10, 
            nov = 11,
            dec = 10
        }

        static void Main(string[] args)
        {
            Console.WriteLine("请输入月份");
            string str = Console.ReadLine();
            Console.WriteLine(Convert.ToInt32((Month)Enum.Parse(typeof(Month), str)));

            Console.ReadLine();           
        }