
#include<bits/stdc++.h>

using namespace std;

double a,b;

bool input(){
  if(!(cin>>a>>b))return false;
  return true;
}

double solve(){
  double t = 3.305785;
  return a*b/t;
}

int main(){

  while(input()){
    //cout<<solve()<<endl;
    printf("%.9lf\n",solve());
  }
}