#include <iostream>
#include <iomanip>
#include <vector>
#include <algorithm>
#include <string>
#include <cstdio>
#include <cmath>
using namespace std;

int main()
{
	int a, b;
	double S;
	cin >> a >> b;
	S = a * b / 3.305785;
	cout << fixed << setprecision(6) << S << endl;
}