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class Solution:
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    def isPowerOfTwo(self, n: int) -> bool:
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        if n == 0:
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            return False
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        k = n
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        while k != 1:
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            if k % 2 != 0:
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                return False
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            k = k // 2
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        return True
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        count = 0
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        for i in range(33):
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            mask = 1 << i
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            if mask & n:
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                count += 1
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            if count > 1:
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                return False
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        if count == 1:
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            return True
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        return False