#include <iostream>
#include <thread>
#include <mutex>

using namespace std;

int count = 0;
std::mutex mtx;

void foo(){
    for(int i = 0; i < 100000000; i++){
        // std::lock_guard<std::mutex> lock(mtx);
        count++;
    }
}

int main(){
    std::thread t1(foo);
    std::thread t2(foo);
    std::thread t3(foo);
    std::thread t4(foo);

    t1.join();
    t2.join();
    t3.join();
    t4.join();

    cout << count << endl;

    return 0;
}