I think I can not get AC because of "Enter"  key on Windows  is "\r\n"  and C++ scanf()  reads it as "\n"  and printf()  writes "\n" as "\r\n".
So,  if in input is some "\n",  then I would read it as "\n" and then print it as "\r\n"!!!  I don't know how to fix that.
Also there were problems with EOF-character.