7. In any $m$ consecutive natural numbers, if there must be a number whose sum of digits is a multiple of 6, then the smallest $m$ is


【Answer】9
【Explanation】If it is $1,2,3,4,5,6$, then there are at most six numbers, so 1 must have numbers "in front" of it, which are $9 \cdots 9$. Since the remainder of $\mathrm{n}$ nines divided by 6 is 0 or 3, it can only be 3, so we can infer two more numbers in front. Assuming the number of 9s is one, it can be $7,8,9,10,11,12,13,14$, and one more number is needed. Therefore, the minimum value of $m$ is 9.