program Files;

  function VariousChars(s: string): boolean;
  var
    i: integer;
    Res: boolean;
  begin
    Res := (length(s) <= 1);
    for i := 2 to length(s) do
      Res := Res or (s[1] <> s[i]);
    VariousChars := Res;
  end;

var
  G, TempFile: Text;
  SourceFileName: string;
  TempFileName: string;
  LineNumber: integer;
  s: string;
begin
  SourceFileName := 'text.txt';
  TempFileName := 'temp.txt';
  Assign(G, SourceFileName);
  reset(G);
  Assign(TempFile, TempFileName);
  rewrite(TempFile);

  LineNumber := 0;
  while not EOF(G) do
  begin
    readln(G, s);
    Inc(LineNumber);
    if VariousChars(s) then
      writeln(TempFile, s)
    else
      writeln(LineNumber);
  end;
  Close(TempFile);
  Close(G);
  Erase(G);
  Rename(TempFile, SourceFileName);
end.