def sort_even(l: list):
    evens = l[::2]
    odds = l[1::2]
    evens.sort()
    ans = []
    for e, o in zip(evens, odds):
        ans.extend([e, o])
    if len(evens) > len(odds):
        ans.append(evens[-1])
    return ans
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