#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <vector>
#include <algorithm>
#include <string>

using namespace std;

int main(void){
	int a, b;
	double ans;
	cin >> a >> b;
	ans = ( double ) ( a * b ) / 3.305785;
	printf("%.6lf\n",ans);

    return 0;
}