What does this C++ snippet output?

1#include <iostream>
2int main() {
3    int x = 3;
4    const int& a = x;   // a binds to x
5    const int& b = 10;  // b binds to a temporary
6    x = 50;
7    std::cout << a << " " << b << "\n";
8    return 0;
9}