Write a method that accepts a string as an input parameter. The method finds all the digits in the string and adds them together. If that sum has more than one digit, find the sum of all the digits in that number. Keep doing this until the sum of the digits is a single digit. For example, "999j999999w999999u999999" has 21 9's which add up to 189. Since this has more than one digit, we will add those digits to get 18. But this still has more than one digit, so we add 1+8 to get 9. The final result is 9.