//this program uses a function that return a value.
#include <iostream>
using namespace std;

//function prototype
int sum (int, int);

int main()
{
	int value1 = 20,	//the first value
		value2 = 40,	//the second value
		total;			//to hold the total
		
	//call the sum function, passing the contents of
	//value1 and value2 as arguments. assign the return 
	//value to the total varible.
	total = sum(value1, value2);
	
	//display the sum of the values.
	cout << "The sum of " << value1 << " and "
		 << value2 << " is " << total << endl;
	return 0;
}

//*******************************************************
// definition of function sum. this function returns	*
// the sum of its two parameters.						*
//*******************************************************

int sum(int num1, int num2)
{
	return num1 + num2;
}