Instructions

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 seven 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.

Moreover, your program should process as many telephone numbers as the user wants.

Use the dialpad below for reference:

This is a $"$Cpp$"$program and the result about the number of the phone, $10$ digit number to make a phone call