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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <math.h>
#include <iostream>
#include <string>
#include<algorithm>
#include<map>
#include <vector>
#include <cassert>
#include<cmath>
using namespace std;


int main() {
	int i, j;
	int N, K;
	int ans = 1;
	cin >> N >> K;
	for (i = 0; i < N; ++i) {
		if (ans <K) {
			ans *= 2;
		}
		else {
			ans += K;
		}
	}
	cout << ans << endl;

}