MODULE Ch2 EXPORTS Main;

IMPORT IO;

VAR
  I,Count:INTEGER;
  
PROCEDURE Phi(N:INTEGER):INTEGER =
  VAR
    I,Result:INTEGER;
  BEGIN
    Result := N;
    I := 2;
    WHILE I <= N DO
      IF N MOD I = 0 THEN
        WHILE(N MOD I = 0) DO N := N DIV I; END;
        Result := Result - (Result DIV I);
      END;
      IF I = 2 THEN I := 1; END;
      INC(I, 2);
    END;
    IF N > 1 THEN Result := Result - (Result DIV N); END;
    RETURN Result;
  END Phi;

PROCEDURE PhiIter(N:INTEGER):INTEGER =
  BEGIN
    IF N = 2 THEN RETURN Phi(N) END;
    RETURN Phi(N) + PhiIter(Phi(N));
  END PhiIter;

BEGIN
  I := 2;
  Count := 0;
  WHILE Count # 20 DO
    IF I = PhiIter(I) THEN
      IO.PutInt(I);
      IO.Put(" ");
      INC(Count);
    END;
    INC(I);
  END;
END Ch2.