class RandomizedSet:

    def __init__(self):
        self.hashmap = {}
        self.list = []


    def insert(self, val: int) -> bool:
        if val in self.hashmap:
            return False

        self.list.append(val)
        self.hashmap[val] = len(self.list) - 1
        return True

    def remove(self, val: int) -> bool:

        if val not in self.hashmap:
            return False

        idx = self.hashmap[val]
        self.list[idx], self.list[-1] = self.list[-1], self.list[idx]
        self.hashmap[self.list[idx]] = idx

        self.list.pop()
        del self.hashmap[val]
        return True

    def getRandom(self) -> int:
        import random
        return random.choice(self.list)