#include <iostream>
#include <algorithm>
#include <cstdio>
#include <string>

#define ll long long

using namespace std;

int dp[1000001];

int main(){

  int m,n;
  cin>>m>>n;
  printf("%.8lf\n",((double)m+(double)(1.000000000/3.000000000)*((double)n)));

   return 0;
}