#include<iostream>
#include<iomanip>

using namespace std;

int main()
{
  long double hebe = 3305785;
  long double a,b;
  long double c;
  cin >> a >> b;
  c = (a*b*1000000)/(double)hebe;
  cout << setiosflags(ios::fixed) << setprecision(4) << c << endl;
}