A spelling alphabet is a set of words, each of which stands for one of the 26 letters in the alphabet. While many letters are easily misheard over a low quality or noisy communication channel, the words used to represent the letters in a spelling alphabet are generally chosen so that each sounds distinct and is difficult to confuse with any other. The NATO phonetic alphabet is a widely used spelling alphabet. Each letter and its associated word is shown in Table 8.1. Write a program that reads a word from the user and then displays its phonetic spelling. For example, if the user enters Hello then the program should output Hotel Echo Lima Lima Oscar. Your program should use a recursive function to perform this task. Do not use a loop anywhere in your solution. Any non-letter characters entered by the user should be ignored.