#include <cstdio>
#include <iostream>
#include <string>
#include <cstdlib>
#include <vector>
#include <algorithm>
#include <functional>
#include <iomanip>
using namespace std;

int main()
{
	int a, b;
	cin >> a >> b;
	cout << (a + b) / 2 << endl;
}
