#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;
}