What does this C++ snippet output?

1#include <iostream>
2int main() {
3    int x = 6;
4    const int& r = x;   // auto& would keep const
5    auto v = r;         // auto drops const+ref: copy
6    v = 100;
7    std::cout << r << " " << v << "\n";
8    return 0;
9}