import java.util.Scanner;

public class No560 {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double M1 = sc.nextDouble();
		int N = sc.nextInt();
		double M = M1;
		for(int i = 1;i <= N;i++) {
			M1 = M;
			M = ((double)1/3) * (M1*2 + M1 + 1);
		}
		System.out.println(M);
	}
}