FIX = """
Add more test cases.
"""
def vowels_count(s):
    vowels = "aeiouAEIOU"
    n_vowels = sum(c in vowels for c in s)
    if s[-1] == 'y' or s[-1] == 'Y':
        n_vowels += 1
    return n_vowels
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