Fix Teen

Given 3 int values, a b c, return their sum. However, if any of the values is a teen -- in the range 13 to 19 inclusive -- then that value counts as 0, except 15 and 16 do not count as a "teens" and should therefore still be added. Write a separate helper function "fixTeen(n)" that takes in an integer value and returns that value fixed for the teen rule. In this way, you avoid repeating the teen code 3 times (i.e. "decomposition").

noTeenSum(1, 2, 3) → 6
noTeenSum(2, 13, 1) → 3
noTeenSum(2, 1, 14) → 3
noTeenSum(2, 15, 14) → 17