Python fibonacci number
Question: This is not a homework question, i'm simply trying to learn. Trying to write a
simple program that reads in 2 numbers.

Compute the Nth fibonacci number and Mth fibonacci number and then find the
greatest common factor of those two numbers.

Must ensure user types in a positive number and then asks again if the user
doesn't


Answer: 
    import collections
    
    def compute():
        m,n = -1, -1
        while m<0: m = int(input("enter a positive number for m: "))
        while n<0: m = int(input("enter a positive number for n: "))
        a, b = 1,1
        collections.deque(((globals().__setitem__('temp', a+b), 
                            globals().__setitem__('a', b), 
                            globals().__setitem__('b', temp), 
                            globals().__setitem__('mth', b if i==m else globals().get('mth', None)), 
                            globals().__setitem__('nth', b if i==m else globals().get('nth', None))) 
                           for i in range(2, n+1)), 
                          maxlen=0)
        return max(i for i in range(1, nth+1) if not mth%i and not nth%i)
    

