A very simple program that calculates the result of your string input.
This program recursively divides the string input to "left" and "right" pieces, then according to the operands it manages to return the output of the string input. Note that the code is not much elegant. I will probably refactor this in the future, but not right now. This was a simple holiday practice for me, and this manages to do the job. Thanks for being interested in anyways,