public class fib2 {
    public static long getSum(long n) {
        long sum = 0;
                long temp = 0;
                long current = 1;
                long prev = 0;

        while(current < n)
                {
                    temp = current;
                    current = current + prev;
                    prev = temp;
                    if(current % 2 == 0)
                        sum += current;
                }
        return sum;
    }
    public static void main(String[] args) {
        System.out.println(getSum(4000000));
    }
}