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

using namespace std;

int main() {
  int M, N;
  cin >> M >> N;
  if (N == 0) {
    cout << M << endl;
    return 0;
  }

  long double kitaichi = M;
  for (int i = 0; i < N; i++) {
    kitaichi = (kitaichi * 2 + kitaichi + 1) / 3.0;
  }
  cout << fixed;
  cout << setprecision(10);
  cout << kitaichi << endl;
  return 0;
}