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
#include <stdio.h>

int main()
{
	int n, k, x=1;
	
	scanf("%d %d", &n, &k);
	
	while(n--){
		if(x < k) x *= 2;
		else x += k;
	}
	
	printf("%d", x);
	
	return 0;
}