#include <iostream>
#include <iomanip>
using namespace std;

double dp[1000][3];
int main(){
	int m,n;cin>>m>>n;
	if(!n){
		cout << m << endl;
		return 0;
	}
	dp[0][0] = m*2;
	dp[0][1] = m+1;
	dp[0][2] = 0;
	for(int i = 1; n > i; i++){
		double t = (dp[i-1][0]+dp[i-1][1]+dp[i-1][2])/3;
		dp[i][0] = t*2;
		dp[i][1] = t+1;
		dp[i][2] = 0;
	}
	cout << fixed << setprecision(10) << (dp[n-1][0]+dp[n-1][1]+dp[n-1][2])/3.0 << endl;
}