#include <iostream>

int& square(int& x) {
    x = x * x;
    return x;
}

int square2(int& x) {
    return x * x;
}

int main() {
     int&& q = 5;
     int& r = q;
     int& s = square(r);
     int t = square2(r);
     
     std::cout << q << " " << r << " " << s << " " << t;  // 25 25 25 625
}