#include <cstdio>
#include <cstdlib>
using namespace std;

const static double TSUBO_METER = 3.305785;
int main() {
  int a, b;

  scanf( "%d%d", &a, &b );
  printf( "%.7f\n", a * b / TSUBO_METER );

  return EXIT_SUCCESS;
}