(function (input) {
    var inputs = input.replace(/\r/g, '').split("\n")[0].split(' '),
        a = parseInt(inputs.shift()),
        b = parseInt(inputs.shift()),
        square = a * b,
        tsubo = square / 3.305785;

    console.log(tsubo.toFixed(6));
})(require("fs").readFileSync("/dev/stdin", "utf8"));