# -*- coding: utf-8 -*-
# Не правильная версия
import threading, time, sys
killed = False
lock = threading.Lock()
def x(n):
global lock
print(n, "started")
while not killed:
lock.acquire()
print(n)
lock.release()
threading.Thread(target=x, args=[1]).start()
threading.Thread(target=x, args=[2]).start()
sys.stdin.readline()
killed = True