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 <iostream>
#include <algorithm>
#include <climits>
#include <numeric>
#include <iomanip>
#include <cmath>
#include <vector>
#include <set>
#include <unordered_set>
#include <queue>
#include <deque>
#include <stack>
#include <map>
#include <unordered_map>
 
#define barsik ios::sync_with_stdio(false)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
typedef long long ll;
typedef std::vector<int> vi;
typedef std::pair <int, int> pii;
typedef std::unordered_set <int> u_si;
const double PI = acos(-1);
const long double EPS = 1e-9;
using namespace std;


void solve(){
    int n, k;
    cin >> n >> k;
    int ans = 1;
    while (n--) {
        if(2 * ans < ans + k) ans *= 2;
        else ans += k;
    }
    cout << ans;
}
int main(){
    int q = 1;
    //cin >> q;}
    while(q--) solve();
}