#include <iostream>
using namespace std;
void main()
{
	float a, b, s;
	cout << "Vvedit pershe chyslo:\n";
	cin >> a;
	cout << "Vvedit druge chyslo:\n";
	cin >> b;
	s = (a + b) / 2;
	cout << "Seredne =" << s << "\n";
}