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from random import randint
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class Solution:
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    def __init__(self, m: int, n: int):
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        self.m = m
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        self.n = n
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        self.ones = set()
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    def flip(self) -> List[int]:
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        i, j = randint(0, self.m - 1), randint(0, self.n - 1)
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        while (i, j) in self.ones:
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            i, j = randint(0, self.m - 1), randint(0, self.n - 1)
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        self.ones.add((i, j))
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        return [i, j]
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    def reset(self) -> None:
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        self.ones.clear()