(* a sample program #2 *)
MODULE sample2;
  FROM InOut IMPORT ReadInt, WriteInt, WriteLn, WriteString;
  VAR i, sum: INTEGER;
  PROCEDURE count( VAR n, sum: INTEGER);
    VAR i: INTEGER;     (* local variable *)
  BEGIN
    i: = 1;
    sum := 0;
    WHILE i <= n DO     (* set-up the loop *)
      sum := sum + i;
      i := i + 1;
    END
  END count;
BEGIN
  ReadInt(i);           (* get i *)
  count(i, sum);        (* call count *)
  WriteInt(sum, 1);     (* write result *)
  WriteLn;
END sample2.