Interacting with the server via socket

Question

There is a server that gives a welcome message and the first simple arithmetic problem in Chinese when you connect to it:

欢迎来到中文房间 
你必须解决成千上万的案件 
九加零

The first two lines are permanent. They are given at each new connection and do not change. At the same time, the task text (the last line) is different every time. It has either 3 or 5 characters. In the first case, the 1st and 3rd character are numbers from 0 to 9, the 2nd character is a + or - operator. In the second case, the first two characters stand for a module. I have written a code containing a solution function. But I have a problem with passing the answer and getting a new problem. The thing is that after solving the nth task in the answer I have to get the key instead of the task.

import socket


letters = ['零', '一', '二', '三', '四', '五', '六', '七', '八', '九', '十', '十一', '十二', '十三', '十四', '十五', '十六', '十七'
            , '十八', '十九', '二十']
numbers = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20]
ops = {'加': '+', '减': '-'}
chinese2num = dict(zip(letters, numbers))
num2chinese = dict(zip(numbers, letters))


def answer(data):
    task = data
    if len(task) == 30:
        task = task[24:29]
    elif len(task) == 28:
        task = task[24:27]
    else:
        print(f'flag: {data}')
        return False
    if len(task) == 5:
        num1 = task[2]
        num1 = chinese2num[num1]
        operation = task[3]
        operation = ops[operation]
        num2 = task[4]
        num2 = chinese2num[num2]
        if operation == '+':
            result = num1 + num2
        if operation == '-':
            result = num1 - num2
        result = abs(result)
        result = str(result)
        print(result)
        return result
    elif len(task) == 3:
        num1 = task[0]
        num1 = chinese2num[num1]
        operation = task[1]
        operation = ops[operation]
        num2 = task[2]
        num2 = chinese2num[num2]
        if operation == '+':
            result = num1 + num2
        if operation == '-':
            result = num1 - num2
        result = num2chinese[result]
        result = str(result)
        print(result)
        return result


sock = socket.socket()
sock.connect(('<ip>', <port>))

n = True
while n:
    data = sock.recv(1024).decode()
    print(data)
    ans = answer(data)
    if ans == False:
        break
    else:
        sock.send(ans.encode())
sock.close()

I'm stuck at the stage where I get the second task. That is, I sent the solution, the connection is not broken, but I can't get a new task.