#include <mutex>
#include <thread>

int main()
{
	std::mutex m1, m2;
	int i = 0;
	
	std::thread t1([&]{ m1.lock(); i = 1; m1.unlock(); });
	std::thread t2([&]{ m2.lock(); i = 2; m2.unlock(); });
	
	t1.join();
	t2.join();
}