Задана матрица a(i;j), (i=1,3; j=1,4) . Найти максимальное значение суммы элементов столбцов матрицы и определить номер столбца — QBasic(Бейсик)

DIM a(3, 4)
RANDOMIZE TIMER
FOR i = 1 TO 3
    FOR j = 1 TO 4
        a(i, j) = INT(RND * 10)
    NEXT
NEXT
PRINT "matrica"
FOR i = 1 TO 3
    FOR j = 1 TO 4
        PRINT a(i, j); " ";
    NEXT
    PRINT
NEXT
max = 0
FOR j = 1 TO 4
    sum = 0
    FOR i = 1 TO 3
        sum = sum + a(i, j)
    NEXT
    IF sum > max THEN max = sum: stolb = j
NEXT
PRINT "max summa="; max
PRINT "v stolbce "; stolb