Write a program to generate personalized junk mail. The program takes input both from an input file and from the keyboard. The input file contains the text of a letter except the name of the recipient is indicated by the three characters #N#. The program asks the user for a name and then writes the letter to a second file but with the three letters #N# replaced by the name. The three-letter string #N# will occur exactly once in the letter.(Will occur many times in our program) Hint: Have your program read from the input file until it encounters the three characters #N#, and have it copy what it reads to the output file as it goes. When it encounters the three letters #N#, it then sends output to the screen asking for the name from the keyboard. You should be able to figure out the rest of the details. Your program should define a function that is called with the input and output streams as arguments. Additional requirements: We are going to allow the three letters #N# occur many times in the letter. All occurrences should be replaced with the recipient