#include <iostream>
#include <iomanip>
#include <cmath>

int main() {
    using namespace std;
    double m;
    int n;
    cin >> m >> n;

    for (int i = 0; i < n; i++) {
        m = 2 * m + m + pow(3., (double)i);
    }
    cout << fixed << setprecision(9) << m / pow(3., (double)n) << endl;
}