#include <iostream>
using namespace std;

/*

	Project Euler
	Problem 2:
	"Each new term in the Fibonacci sequence is generated by adding the
	 previous two terms. By starting with 1 and 2, the first 10 terms will
	 be:
		1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
	 Find the sum of all the even-valued terms in the sequence which do
	 not exceed four million."

*/

void main () {

	long number_limit	= 4000000;	// Find the sum of the...not exceed x
	long fibonacci_sequence [1000];
	long sum			= 0;

	// Generate an array holding the fibonacci sequence
	fibonacci_sequence[0] = 1;
	fibonacci_sequence[1] = 2;

	long fibonacci_index = 2;
	while (fibonacci_sequence[fibonacci_index - 1] + fibonacci_sequence[fibonacci_index - 2] < number_limit) {
		fibonacci_sequence[fibonacci_index] = fibonacci_sequence[fibonacci_index - 1] + fibonacci_sequence[fibonacci_index - 2];

		fibonacci_index++;
	}

	// Now, find the sum of all even numbers in the sequence that are less
	// than 4 million.
	for (long i = 0; i < fibonacci_index; i++) {
		if (fibonacci_sequence[i] % 2 == 0 && fibonacci_sequence[i] < number_limit) {
			sum += fibonacci_sequence[i];
		}

	}

	cout << sum << endl;

	int stopCommandPromptFromClosing;
	cin >> stopCommandPromptFromClosing;

}