A/B + C/D

I was contacted by a friend that maintains an online judge, asking about the solution to a particular problem that has existed for how many days on an “easy” section.

Basically, the problem is this: given positive integers A, B, C, D, compute A/B + C/D and simplify it. You are guaranteed that if you represent A/B + C/D = E/F in lowest terms, then all of A,B,C,D,E,F fit in p-bit integers (in the problem, p = 64). Your task is to find this E and F.