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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 _memo(f):
 """Return a function like f but caching its results. Its arguments must be hashable."""

    memos = {}
    def memoized(*args):
        try: return memos[args]
        except KeyError:
            result = memos[args] = f(*args)
            return result
    return memoized