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;
public class Main{
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
  int N = sc.nextInt();
  int K = sc.nextInt();
  int A = 1;
  int B = 0;
  while(A <= K){
    A *= 2;
    B += 1;
  }
  if(N > B) {
  System.out.println((int)Math.pow(2,B) + K*(N-B));
  }
  else if(N <= B)System.out.println((int)Math.pow(2,N));
}
}