#include	<iostream>
#include	<cstdio>

using namespace std;

int main(void) {
	while(1) {
		int a, b;
		double area, tsubo;
		
		cin >> a;
		if( cin.eof() )		break;
		
		cin >> b;
		area = a * b;
		
		tsubo = area / 3.305785;
		printf("%.6f\n", tsubo);
	}
	
	return 0;
}