#include <iostream>

int main() {
    int value{4};
    int& r{value};
    auto copy = r;
    auto& same = r;
    const auto& read = r;
    copy = 9;
    same = 7;
    std::cout << value << ' ' << copy << ' ' << same << ' ' << read << '\n';
    value = 10;
    std::cout << value << ' ' << copy << ' ' << same << ' ' << read << '\n';
    return 0;
}