class TwoSum:

    def __init__(self):
        self.nums = defaultdict(int)

    def add(self, number: int) -> None:
        self.nums[number]+= 1

    def find(self, value: int) -> bool:
        for num in self.nums:
            if (value - num) in self.nums:
                # check for duplicates
                if value-num == num:
                    return self.nums[num] > 1
                else:
                    return True
        return False