Given a nonnegative int variable n, calculate and print out the sum of the digits of n. For example, if
n has the value 1234, since 1 + 2 + 3 + 4 = 10, your program should print 10.
n % 10 to extract the digit in the ones place of n and use
integer division / to remove the last digit from a number.
Stuck? You may find these lessons helpful: