using System;
using System.IO;
class Class1
{
[STAThread]
static void Main(string[] args)
{
FileStream fsSrc = File.OpenRead("s.txt");
BinaryReader rdr = new BinaryReader(fsSrc);
FileStream fsDest = File.Open("d.txt", FileMode.Create);
MemoryStream memStream = new MemoryStream();
int curChar = 0;
while ((curChar = rdr.Read()) != -1)
{
memStream.WriteByte(Convert.ToByte(curChar));
}
for (int i = 0; i < memStream.Length / 2; ++i)
{
byte tempTop, tempBottom;
memStream.Seek(i, SeekOrigin.Begin);
tempTop = (byte)memStream.ReadByte();
memStream.Seek(-i - 1, SeekOrigin.End);
tempBottom = (byte)memStream.ReadByte();
memStream.Seek(-1, SeekOrigin.Current);
memStream.WriteByte(tempTop);
memStream.Seek(i, SeekOrigin.Begin);
memStream.WriteByte(tempBottom);
}
memStream.Seek(0, SeekOrigin.Begin);
byte[] memBytes = memStream.ToArray();
BinaryWriter bw = new BinaryWriter(fsDest);
bw.Write(memBytes);
bw.Close();
rdr.Close();
}
}