% Calculates n+(n-1)+(n-2)+...+1

PROCEDURE Main;
VAR n,resultat;

  PROCEDURE Sum;
  VAR m;

  BEGIN

    OUTPUT n;

    ASSIGN n > m;

    IF m-2 THEN
      ASSIGN n-1>n;
      CALL Sum;
      ASSIGN resultat+m>resultat;
    FI;
    IF 1 - m THEN
      ASSIGN 1 > resultat;
    FI;
  END;

  BEGIN
    INPUT n;
    CALL Sum;
    OUTPUT resultat;
  END;