#include <iostream>
#include <cstdlib>
using namespace std;

int main()
{
	int i {10};
	int c {i}; //The value of c is a copy of the value of i.

	//At this point, there are two ints in memory.

	++c;       //This has no effect on the value of i.
		  
	cout << "i == " << i << "\n"
		<< "c == " << c << "\n\n";

	int j {20};
	int& r {j}; //The value of r is always the same value as the value of j.
		    
	//At this point, there is only one int in memory
	//(not counting the i and c from the previous example).
	//To access this int, we can write either j or r.

	++j;        //Increment the value of j.
	++r;        //Another way to increment the value of j.

	cout << "j == " << j << "\n"     //Output the value of j.
		<< "r == " << r << "\n"; //Another way to output the value of j.

	return EXIT_SUCCESS;
}