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.*;
import java.io.*;
public class Main{
  public static void main(String args[]){
  	Scanner Sc=new Scanner(System.in);
    int N=Sc.nextInt();
    int K=Sc.nextInt();
    int dp[]=new int[N+1];
    dp[0]=1;
    for(int i=1;i<=N;i++){
    	dp[i]=Math.min((dp[i-1]*2),(dp[i-1]+K));
    }
    System.out.println(dp[N]);
  }
}