#include <iostream>
#include <cstdio>
using namespace std;
#define tubo 3.305785
 
double ans(int a , int b ){
  double res;
 
  res = (a*b)/tubo;
 
  return res;
}
 
int main(void){
  int a,b;
 
  cin >> a >> b;
  printf("%.6f\n" ,ans(a,b));
 
  return 0;
}