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[] 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]);
    }
}


