#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>
#include <cmath>
#include <stack>
#include <cctype>
using namespace std;

int main() {

	double m=0,n=0;

	cin>>m>>n;



	cout<<setprecision(17)<<m+n/3.0<<endl;

	return 0;
}