#include <bits/stdc++.h>
using namespace std;
const double PI = acos(-1);
int main(){
  cout << fixed << setprecision(20);
  double H, R;
  cin >> H >> R;
  R *= PI * 2;
  double ans = -8.245 + 6.807 * H + 7.073 * R;
  cout << ans << endl;
}