program UpperLower;
var
  S: String;
  I: Integer;
begin
  while not Eof do begin
    readln(S);
    for I:=1 to Length(S) do begin
      case S[I] of
        'a'..'z': Dec(S[I],$20);
        'A'..'Z': Inc(S[I],$20);
      end;
    end;
    writeln(S);
  end;
  writeln('EOF.');
end.