Create web interface for C# program - repost

I would like to create a simple website to host my C# program. Website only needs two pages -- input/homepage and generated output page. About the C# program: -It is currently written as a console program, so modification may be needed to implement correct web protocol. -The program needs to be constantly running -- it establishes a connection, so I do not want a new instance of the program started up every time it is called from the webpage. -Program input is a single string. -Program output returns multiple lines of text retrieved from a server and currently outputs to console. What I want on the webpage interface: - User will input the string into a text box and hit "enter". The resulting webpage should then be generated containing all of the program output. I will provide more details on webpage formatting later on. - The interface should be able to handle multiple user requests. The program takes around 10 seconds to process each request. Please see attached image for rough template. If you have additional questions, feel free to message me. Thanks