#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<vector>
#include<string>
#include<sstream>
#include<cmath>
#include<numeric>
#include<map>
#include<stack>
#include<queue>
using namespace std;
int main(void) {
  int a, b;
  cin >> a >> b;
  printf("%.10lf\n", (double) a*b / 3.305785);

  return 0;
}





// EOF