#include <iostream>
using namespace std;

int evenfibonacci()
{
    int result = 2;
    int last[2] = {1, 2};
    for (int k = 3; k <= 33; ++k) {
        int value = last[0] + last[1];
        if (value % 2 == 0) {
            result += value;
        }
        last[0] = last[1];
        last[1] = value;
    }
    return result;
}

int main()
{
	cout << evenfibonacci();
}