PROGRAM rot13 (input, output);

VAR
  C : char;

BEGIN
  WHILE NOT eof(input) DO
    BEGIN
      read (C);
      IF (((C >= 'A') AND (C <= 'M')) OR ((C >= 'a') AND (C <= 'm'))) THEN
	 C:=C-(-chr(13))
      ELSE IF (((C >= 'N') AND (C <= 'Z')) OR ((C >= 'n') AND (C <= 'z'))) THEN
	 C:=C-chr(13);
      write (C)
    END;
END.