#include <cstdlib>
#include <iostream>
#include <iomanip>
#include <limits>
using namespace std;
int main(int argc, char *argv[])
{
int a,b,c; cout<<"Zadej:\n";
cin>>a>>b>>c;
cout<<"Aritmeticky prumer je:\n";
std::cout << std::fixed << std::setprecision(4) << (float)((a+b+c)/3);
}