//1
#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <cmath>
#include <map>
#include <set>
#include <string>
#include<bitset>

using namespace std;
#define loop(i,n) for(int i = 0; i < (n); ++i)
#define loops(i,f,n) for(int i = (f); i < (n); ++i)
#define INF 9999999
#define lint long long int
#define VEC vector<int>
#define VEC2 vector<vector<int>>

int main()
{
	cin.tie(0);
	ios::sync_with_stdio(false);
	int a, b;
	cin >> a >> b;
	cout << (a + b) / 2<<endl;
}
