uses crt;
var
  file1, file2: file of char;
  filename1, filename2: string[30];
  Thing1, Thing2: char;
  Pos: LongInt;

begin
  if ParamCount = 2 then begin
    ClrScr;
    Filename1 := Paramstr(1);
    Filename2 := Paramstr(2);
    Assign(File1, filename1);
    Assign(File2, filename2);
    Reset(File1);
    Reset(File2);
    if FileSize(File1) = FileSize(File2) then
      for Pos := 0 to FileSize(File1) - 1 do begin
        Read(File1, Thing1);
        Read(File2, Thing2);
        If Thing1 <> Thing2 then Writeln(Pos, ' ', Thing1, ' ', Thing2);
      end;{for}
    Close(File1);
    Close(File2);
  end else Writeln('Error');{if paramcount}
end.