Your program needs to take a manually input ciphertext message (i.e., multiple blocks of English letters separated by spaces between blocks) and a manually specified vocabulary text file name from the command line user interface, and output the deciphered plaintext message and the recovered encryption key to the command line interface. The test ciphertext will be chosen such that all the corresponding plaintext words are from the vocabulary file (but not necessarily from a sentence). As an example:

User-input ciphertext message: jo dpnqvufs xpsme

User-specified vocabulary text file:

Innovations in the world of computer technology have changed our lives drastically over the past few decades. Its hard to believe that twenty years ago few people had heard of the internet. Today, computer scientists are busy developing new ideas that will shape the future. Computer scientists specialize in the software side of computing, focusing on writing new programs that allow computer applications to run faster and more efficiently. You might work for a security company, creating technology that reduces the risks of viruses and hackers, or develop flight simulation exercises that allow airline pilots to practice managing flight problems. Computer engineers deal with both software and hardware. As a computer engineer, you could design entire computer systems and networks, making sure that the hardware, or physical equipment, is capable of running the appropriate software. You might build devices such as retinal scanners that identify people by checking their eyes, or you could design computers that are incorporated into prosthetic devices to aide people with disabilities. Those who continue onward to obtain a graduate degree in either computer science or computer engineering learn to advance the frontiers of science. With an MS or PhD, you will invent the new technologies that enable the next generation of software and computing devices. 

Output:

o Key: 1

o Plaintext Message: in computer world