Welcome to this series of Scheme challenges!
In every challenge you will have to solve the given problem by writing Scheme code that returns a lambda which produces the required output when given the specified input.
There is a catch: you may only use a small amount of variables, procedures and special-forms. Literals such as numbers and strings are still allowed of course.
Go ahead and experiment with the first challenge and see how it works! It is a sanity check to make sure you understand what you need to do. Contact one of the organisers if you have issues solving it!

Please refrain from writing infinite loops, I didn't feel like solving the halting problem...