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class NumArray:
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    def __init__(self, nums: List[int]):
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        self.nums, Sum = [], 0
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        for num in nums:
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            Sum += num
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            self.nums.append(Sum)
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    def sumRange(self, left: int, right: int) -> int:
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        return (
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            self.nums[right] - self.nums[left - 1]
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            if left - 1 >= 0
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            else self.nums[right]
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        )