
Score : 200 points
Problem StatementSquare1001 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.
InputInput is given from Standard Input in the following format:
N
K
OutputPrint the minimum possible value displayed in the board after N operations.
Sample Input 14
3
Sample Output 110
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.  
Sample Input 210
10
Sample Output 276
The value will be minimized when the operations are performed in the following order: A, A, A, A, B, B, B, B, B, B.
In this case, the value will change as follows: 1 → 2 → 4 → 8 → 16 → 26 → 36 → 46 → 56 → 66 → 76.  
By the way, this contest is AtCoder Beginner Contest 076.
