写专属或加密程序。 程序应该采取作为输入由程序然后加密的文件名。 程序应该要求用户输入密钥，应该用于加密文件。

程序的输出应该进入一个文件以同一个文件名，但.ENC引伸。-Write an exclusive-OR encryption program. The program should take as input a filename that is then encrypted by the program.　The program should ask the user to input an encryption key, which should be used to encrypt the file.

The output of the program should go into a file with the same filename but a .ENC extension.