#include <thread>
    #include <vector>
    #include <iostream>
    using namespace std;
    
    void fun(vector<int> & v) {
    	v.push_back(13);
    }
    
    int main(){
    	vector<int> v;
    	thread t([&](){ fun(v); });
    	t.join();
    	cout << v.size();
    }