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 javax.sql.rowset.serial.SerialArray;

public class Main {

		public static void main(String[] args){
			
			Scanner sc = new Scanner(System.in);

			int N = sc.nextInt();
			int K = sc.nextInt();

			int ans = 1;
		    for(int i = 0; i < N; i += 1){
		        if(ans < K){
		        	ans = ans * 2;
		        }else{
		        	ans = ans + K ;
		        }
		    }
		    System.out.println(ans);

		}
}
