#include<cstdio>
#include<string>
#include<algorithm>
using namespace std;

#define rep(i,n) for(int i=0; i<n; i++)

int main(){
    int a, b;
    scanf("%d %d", &a, &b);
    double S = 1. * a * b / 3.305785;
    printf("%.6lf\n", S);
    return 0;
}