class MyHashSet:
    myset = set()
    def __init__(self):
        self.myset = set()
    def add(self, key: int) -> None:
        return self.myset.add(key)

    def remove(self, key: int) -> None:
        return self.myset.discard(key)

    def contains(self, key: int) -> bool:
        return (key in self.myset)