#include <iostream>
#include <memory>
#include <vector>

int main() {
    auto a = std::make_shared<std::vector<int>>();

    for (int i = 0; i < 3; i++) {
        a->push_back(i);
    }
    
    for (const auto& i : *a) {
        std::cout << i << std::endl;
    }
    
    return 0;
}