I was thinking, this not only could be very fun, but also can help us composers with our techniques. So think of it as a game and an exercise.
There are several ways to do it, I have a chord progression here and basically you can come up with a melody to it based purely on what you think the theme sounds like!
-Make a theme you feel suits the chord progression
-Can change instruments if you feel like it
-Have fun!
EDIT:
Am- C (i don't know what this chord is exactly)- Fmaj- Cmaj