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

int average(int a, int b);  //function declaration

int main()
{
	int i = 10;
	int j = 20;
	int k = average(i, j);

	cout << average(j, 40) << "\n";
	return EXIT_SUCCESS;
}

int average(int a, int b)   //function definition
{
	return (a + b) / 2; //3 fewer pairs of parentheses than line 5 of macro.C
}