#include <iostream>
#include <vector>

int main() {
    std::vector<int> original{2, 4};
    auto copied = original;
    int& alias = original.at(0);
    alias = 9;
    std::cout << "Original: " << original[0] << "; copy: " << copied[0] << '\n';
    std::cout << "Elements: " << original.size() << '\n';
}