Modify the following program so that the user can specify an encryption key other than $3$ with a $-k$ option. For example:

java CaeserCipher $-$k$15$ input.txt output.txt

$\backslash$table$[[,$infile$2.$txt$,$infile$3.$txt$]]$

import java.io$.$File;

import java.io$.$FileNotFoundException;

import java.io$.$PrintWriter;

import java.util.Scanner;

$\frac{?}{?}****$

This program encrypts a file using the Caesar cipher.

$*/$

public class CaesarCipher

$\{$

public static void main$($String $[]$ args$)$ throws FileNotFoundException

$\{$

String $$ my$\_$args $=$ new String$[3]$;

Scanner console $=$ new Scanner$($System$.$ in$)$;

my$\_$args $[0]=$ console. next $()$;