#include <bits/stdc++.h>

using namespace std;

int main() {
    double m;
    int n;
    cin >> m >> n;
    while (n--) {
        double nm = m * 2 + (m + 1);
        m = nm / 3;
    }
    cout << fixed << setprecision(10) << m << endl;
    return 0;
}