Lê o código com atenção

import threading

counter = 0
lock = threading.Lock()

def bump():
    global counter
    with lock:
        counter += 1

threads = [threading.Thread(target=bump) for _ in range(5)]
for t in threads: t.start()
for t in threads: t.join()
print(counter)

O que o programa vai imprimir? Escreve aqui: