DEFINE VARIABLE i AS INTEGER NO-UNDO.
DEFINE VARIABLE i_floor AS INTEGER INITIAL 0 LABEL "floor number" NO-UNDO.
DEFINE VARIABLE i_basement AS INTEGER INITIAL 0 LABEL "basement instruction" NO-UNDO.
DEFINE VARIABLE c_input AS CHARACTER LABEL "Insert instructions" NO-UNDO.
UPDATE c_input VIEW-AS EDITOR INNER-LINES 10 INNER-CHARS 50 WITH FRAME a.
FORM
    i_floor COLON 25
    i_basement COLON 25
    WITH SIDE-LABELS FRAME b.
HIDE FRAME a.
REPEAT i = 1 TO LENGTH(c_input):
    i_floor = i_floor + (IF SUBSTRING(c_input, i, 1) = "(" THEN 1 ELSE -1).
    IF i_floor = -1 AND i_basement = 0 THEN DO:
        i_basement = i.
        DISPLAY i_basement WITH FRAME b.
    END.
END.
DISPLAY i_floor WITH FRAME b.