#include <iostream>

#include <vector>

// for the header file
template<>
int std::vector<int>::sum();

//for the object file
template<>
int std::vector<int>::sum() {
	int s=0;
	for(auto v = this->begin(); v!=this->end(); ++v) s+=*v;
	return s;
}


int main() {
	std::vector<int> numbers;
	numbers.push_back(5);
	numbers.push_back(2);
	numbers.push_back(6);
	numbers.push_back(9);
	
	std::cout << numbers.sum() << std::endl;
	
	return 0;
}