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.

-----Sample Input-----
4
3

-----Sample Output-----
10

The value will be minimized when the operations are performed in the following order: A, A, B, B.

In this case, the value will change as follows: 1 → 2 → 4 → 7 → 10.

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