Найти среднее арифметическое положительных элементов массива A(N,M) — QBasic(Бейсик)

CLS
INPUT "kolvo strok="; n
INPUT "kolvo stolbcov="; m
DIM a(n, m)
RANDOMIZE TIMER
FOR i = 1 TO n
    FOR j = 1 TO m
        a(i, j) = INT(RND * 100) - 50
    NEXT j
NEXT i
FOR i = 1 TO n
    FOR j = 1 TO m
        PRINT a(i, j);
    NEXT j
    PRINT
NEXT i
PRINT
s = 0: k = 0
FOR i = 1 TO n
    FOR j = 1 TO m
        IF a(i, j) > 0 THEN s = s + a(i, j): k = k + 1
    NEXT j
NEXT i
IF k > 0 THEN
    c = s / k
    PRINT "Srednee arifm polozh elementov="; c
ELSE
    PRINT "V massive net polozh elementov"
END IF
END