To make telephone numbers easier to remember, some companies use letters to show their telephone number. For example, using letters, the telephone number 438-5626 can be show as GET LOAN. In some cases, to make a telephone number meaningful, companies might use more than seven letters. For example, 225-5466 can be displayed as CALL HOME, which uses eight letters.
Write a program that prompts the user to enter a telephone number expressed in letters and outputs the corresponding telephone number in digits. If the user enters more than 7 letters, then process only the first seven letters. Also output the -(hyphen) after the third digit. Allow the user to use both uppercase and lowercase letters as well as spaces between words.
Modify question 3 of Assignment 1 to accept a telephone number with any number of letters. The output should display a hyphen after the first 3 digits and subsequently a hyphen (-) after every four digits. Also, modify the program to process as many telephone numbers as the user wants.