#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <string>
#include <sstream>
#include <complex>
#include <vector>
#include <list>
#include <queue>
#include <deque>
#include <stack>
#include <map>
#include <set>
#include <iomanip>
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
using namespace std;

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


