下载后发现是压缩包嵌套，直接编写脚本

# -*- coding: utf-8 -*-
'''
@Author  : Hatanezumi
@Contact : [email protected]
'''

from zipfile import ZipFile

for i in range(999, 0 , -1):
    print(i)
    with ZipFile(f'{i}.zip', 'r') as file:
        file.extractall()

得到1.zip

直接打开得到flag值
flag值：
flag{So_l3og_zzzzziii111ppppp99!}