#include <iostream>
#include <cmath>

using namespace std;

int main(){
  double a,b;
  double t=3.305785;
  cin>>a>>b;
  a*=b;
  cout<<(int)(a/t)<<".";
  a=fmod(a,t);
  for(int i=0;i<6;i++){
    a*=10;
    cout<<(int)(a/t);
    a=fmod(a,t);
  }
  cout<<endl;
  return 0;
}