Дана матрица A(n,n).Найти сумму элементов попадающих в интервал [d,b] — QBasic(Бейсик)

INPUT "razmernost massiva ", n
DIM a(n, n)
FOR i = 1 TO n
    FOR j = 1 TO n
        INPUT "element ", a(i, j)
    NEXT
NEXT
INPUT "interval ot ", d
INPUT "interval do ", b
s = 0
FOR i = 1 TO n
    FOR j = 1 TO n
        IF (a(i, j) >= d) AND (a(i, j) <= b) THEN s = s + a(i, j)
    NEXT j
NEXT i
PRINT "Summa elementov popadayushih v interval ot "; d; "do"; b; "="; s