using System;

public class E2 {
	public static void Main() {
		int sum, last, current, tmp;
		last = 0;
		sum = 0;
		for (current = 1; current < 4000000; tmp = current, current += last, last = tmp) {
			if (current % 2 == 0)
				sum += current;
		}
		System.Console.WriteLine(sum);
	}
}