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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 getkth(self, k):
        "starts from 0"
        if k >= len(self):
            raise IndexError
        k += 1  # self has index -1
        h = len(self.next) - 1
        x = self
        while k:
            while x.next[h] is None or x.count[h] > k:
                h -= 1
            k -= x.count[h]
            x = x.next[h]
        return x.key