#include<iostream>
#include<algorithm>
#include<string>
using namespace std;
int main()
{
	int a = 0;
	int b = 0;
	cin >> a >> b;
	long long int c = a * b * 10000000000 / 3305785;
	cout << c / 10000 << '.' << c % 10000 << endl;
	return 0;
}