using System;

using System.Text;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(MaskName("Petter Pan"));

        Console.WriteLine(MaskName("petter Pan"));

        Console.WriteLine(MaskName("張三"));

        Console.WriteLine(MaskName("王大明"));

        Console.WriteLine(MaskName("李小天"));

        Console.WriteLine(MaskName("蔡佩佩"));

        Console.WriteLine(MaskName("張簡明偉"));

        Console.WriteLine(MaskName("賽德克*巴萊"));

    }

    /// 姓名遮罩包含英文姓名

    /// 

    ///

    /// 姓名

    /// 

    /// 王O名

    private static string MaskName(string val) {

        string maskstr, maskchar;

        maskchar = null;

        //符合英文的模式

        if (Regex.IsMatch(val, "[A-Za-z]"))

        {

            if (val.IndexOf("-") > 1)

            {

                maskstr = val.Split('-')[1];

                val = val.Replace(maskstr, "*");

            }

            if (val.IndexOf(" ") > 1)

            {

                maskstr = val.Split(' ')[1];

                val = val.Replace(maskstr, "*");

            }

        }

        else

        { 

            //中文

            int strlen = val.Length;

            if(strlen==2){

                return val.Substring(0, 1)+"O";

            }

            if(strlen==3){

                return val.Substring(0, 1)+"O"+val.Substring(2, 1);

            }

            if(strlen>=4){

                return val.Substring(0, 2)+"O"+val.Substring(3, strlen-3);

            }           

        }            

        return val;

    }

}