MODULE PerfectNumbers;

FROM SWholeIO IMPORT
  WriteCard;
FROM STextIO IMPORT
  WriteLn;
FROM RealMath IMPORT
  sqrt;

VAR
  N: CARDINAL;

PROCEDURE IsPerfect(N: CARDINAL): BOOLEAN;
VAR
  S, I: CARDINAL;
  SqrtN: REAL;
BEGIN
  S := 1;
  SqrtN := sqrt(FLOAT(N));
  IF N REM 2 = 0 THEN
    S := S + 2 + N / 2;
  END;
  I := 3;
  WHILE FLOAT(I) <= SqrtN - 1.0 DO
    IF N REM I = 0 THEN
      S := S + I + N / I;
    END;
    I := I + 1;
  END;
  IF I * I = N THEN
    S := S + I;
  END;
  RETURN (N = S);
END IsPerfect;

BEGIN
  FOR N := 2 TO 10000 BY 2 DO
    IF IsPerfect(N) THEN
      WriteCard(N, 5);
      WriteLn;
    END;
  END;
END PerfectNumbers.