Square1001 has seen an electric bulletin board displaying the integer 1. He can perform the following operations A and B to change this value:

* Operation A: The displayed value is doubled.
* Operation B: The displayed value increases by K.



Square1001 needs to perform these operations N times in total. Find the minimum possible value displayed in the board after N operations.

Constraints

* 1 \leq N, K \leq 10
* All input values are integers.

Input

Input is given from Standard Input in the following format:


N
K


Output

Print the minimum possible value displayed in the board after N operations.

Examples

Input

4
3


Output

10


Input

10
10


Output

76
import java.util.Scanner;
import java.lang.Math;

class Main {
    
    public static void main(String[] areg) {
        Scanner sc = new Scanner(System.in);
		int N = sc.	nextInt();
		int K = sc.	nextInt();
		sc.close();
        
        long ans = 1;
        for (int i = 0; i < N; i++)
            ans = Math.min(ans * 2, ans + K);
        
        System.out.println(ans);
    }
}