Problem:
Score : 200 points

Problem Statement

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 1

4
3

Sample Output 1

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.

Sample Input 2

10
10

Sample Output 2

76

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.

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;


    class Program
    {
        static void Main()
        {
        int a = 0, b = 0, c = 0, d = 0, e;
        int Out = 0;

        int value = 1;

        //e = int.Parse(Console.ReadLine());
        e = 1;
        /*
            for (int i = 0; i < e; i++)
            {
                string[] str = Console.ReadLine().Split(' ');//2つ以上のスペース区切り入力の取得
                a = int.Parse(str[0]);  //数値で受け取りたい場合は変換する
                //b = int.Parse(str[1]);
                //c = int.Parse(str[2]);
                //d = int.Parse(str[3]);
            }
            */
        a = int.Parse(Console.ReadLine());
        b = int.Parse(Console.ReadLine());
        
        for(int i = 0;i<a;i++)
        {
            if(value * 2 < value + b)
            {
                value = value * 2;
            }
            else
            {
                value = value + b;
            }
        }

        Console.WriteLine(value);
        }
    }