#include <iostream>
#include <math.h>

// do
// {
//    STATEMENTS
// }
// while (CONDITION);
//
//
//
// while (CONDITION)
// {
//     STATEMENTS
// }

int main()
{
	long int n;
	long int total;
	long int i;

	cout << "Enter an integer: ";
	cin >> n;
	//cout << "The fancy formula says " << n*(n+1)/2 << endl;

	// HERE ARE THREE WAYS OF DOING THE SAME THING
	
	total = 0;
	// Order of operations:
	// (1) initialization
	// (2) test loop execution condition
	// (3) stuff inside loop
	// (4) repeat expression is evaluated
	// (5) test loop execution condition
	// (6) stuff inside loop
	// ...
	// for (INITIALIZATION; LOOP EXECUTION CONDITION; REPEAT EXPRESSION)
	for (i = 1; i <= n; ++i)
	{
		total += i;
	}
	
	//total = 0;
	//i = 1;
	//while (i <= n)
	//{
	//	total += i;
	//	++i;
	//}

	//total = 0;
	//while (n > 0)
	//{
	//	total += n;
	//	n--; // same thing as:  n = n - 1;
	//}

	cout << "The total is " << total << endl;
}