#include <iostream>
#include <cstdio>
#define TUBO_UNIT 3.305785
using namespace std;

int main(void) {
    int a, b; cin >> a >> b;
    
    double ans = a*b;
    ans = ans / TUBO_UNIT;
    
    printf("%.7f\n", ans);
    return(0);
}