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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def Strongest_Extension(class_name, extensions):
    """You will be given the name of a class (a string) and a list of extensions. The extensions are to be used to load additional classes to the class. The letters in the extension's name, and let SM be the number of lowercase letters in the extension's name, the strength is given by the fraction CAP - SM. You should find the strongest extension and return a string in this If there are two or more extensions with the same strength, you should choose the one that comes first in the list. For example, if you are given "Slices" as the class and a list of the return 'Slices.SErviNGSliCes' since 'SErviNGSliCes' is the strongest extension (its strength is -1). for Strongest_Extension('my_class', ['AA', 'Be', 'CC']) == 'my_class.AA' """
    strong = extensions[0]
    my_val = len([x for x in extensions[0] if x.isalpha() and x.isupper()]) - len([x for x in extensions[0] if x.isalpha() and x.islower()])
    for s in extensions:
        val = len([x for x in s if x.isalpha() and x.isupper()]) - len([x for x in s if x.isalpha() and x.islower()])
        if val > my_val:
            strong = s
            my_val = val

    ans = class_name + "." + strong
    return ans

