
#include <iostream>
#include <algorithm>
#include <vector>
#include <cstdio>
#include <cmath>
#include <string>
#include <queue>
#include <stack>
#include <sstream>
using namespace std;
int main(){
	int a,b,ans;
	cin>>a>>b;
	ans=(a+b)/2;
	cout<<ans<<endl;
	return 0;
}