我需要将此数组公式（Luhn算法）从16位更改为不确定位数：
=MOD(SUM(IF((MID(A6,ROW(INDIRECT("1:"&LEN(A6))),1))*MOD(ROW(INDIRECT("1:"&LEN(A6))),2) =0,0,MOD((MID(A6,ROW(INDIRECT("1:"&LEN(A6))),1))*MOD(ROW(INDIRECT("1:"&LEN(A6))),2)*2-1,9) +1)+(MID(A6,ROW(INDIRECT("1:"&LEN(A6))),1))*MOD(ROW(INDIRECT("1:"&LEN(A6)))-1,2)),10)=0