#include <iostream> #include <algorithm> #include <vector> #include <map> #include <string> #include <numeric> #include <cstring> #include <cmath> #include <set> #include <queue> #include <stack> const int MOD = 1e9 + 7; const int iINF = 100000000; #define rep(i,n) for(int i=0;i<(n);i++) using namespace std; using ll = long long int; using P = pair<int, int>; using edge = struct{int to; int cost;}; int main() { double ans; double M, N; cin >> M >> N; ans = M + N / 3; printf("%lf\n", ans); return 0; }