from typing import List
def remove_duplicates(numbers: List[int]) -> List[int]:
    import collections
    c = collections.Counter(numbers)
    return [n for n in numbers if c[n] <= 1]
from typing import List
def below_zero(operations: List[int]) -> bool:
    balance = 0
    for op in operations:
        balance += op
        if balance < 0:
            return True
    return False