Pseudo code

 design and write a application using pseudo code, that takes as input a single letter and displays the corresponding digit on the telephone. The letters and digits on a telephone are grouped this way:
2 = ABC 4 = GHI 6 = MNO 8 = TUV
3 = DEF 5 = JKL 7 = PRS 9 = WXY
No digit corresponds to either Q or Z. For the two letters, your application should display a message indication that they are not used on a telephone.
The screen dialog might look like this:
Enter a single letter, and I will tell you what the corresponding digit is on the telephone.
R
The digit 7 corresponds to the letter R on the telephone.
Your code should display a message indication that there is no matching digit for any nonalphabetic character entered by the user. Also, the application should recognize upper or lower case letters