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.util.function.Predicate;

public class Main {

    public static void main(String[] args) {
        new Main().run();
    }


    void run() {
        Scanner cin = new Scanner(System.in);
        int N = cin.nextInt();
        int K = cin.nextInt();
        int now = 1;
        for (int i = 0; i < N; i++){
            //2倍とKを足すのの、値が小さくなる方を採用する
            now = Math.min(now * 2, now + K);
        }
        System.out.println(now);
    }
}
