#include<iostream>

int main(){
	int r, b, g;
	std::cin >> r >> b >> g;
	int ans = 0;
	
	if (b < g)std::swap(b,g);
	if (r < b)std::swap(r, b);
	if (g > b)std::swap(g, b);//r>b>g
	if (r <= 2 && b <= 2 && g == 0){
		std::cout << 0 << std::endl;
		return 0;
	}
	r += b * 2;
	r += g * 2;
	
	std::cout << r/5 << std::endl;
	return 0;
}