Let n be a positive integer consisting of up to 10 digits d_10, d_9,...,d_1.
Write a program to list in one column each of the digits in the number n.
The right-most digit, d_1, should be listed at the top of the column.

Hint: use the fact that digit = n % 10;

Ref: Hanly, Ch. 5, P5, p.287