#include<iostream>
using namespace std;

int main(){
  int n;cin >> n;
  int dp[45];dp[0]=1;dp[1]=1;
  for(int i=2;i<45;i++){
    dp[i]=dp[i-1]+dp[i-2];
  }
  cout << dp[n] << endl;
}


### Prompt

Please create a solution in Cpp to the following problem:

Write a program which prints $n$-th fibonacci number for a given integer $n$. The $n$-th fibonacci number is defined by the following recursive formula:

\begin{equation*} fib(n)= \left \\{ \begin{array}{ll} 1 & (n = 0) \\\ 1 & (n = 1) \\\ fib(n - 1) + fib(n - 2) & \\\ \end{array} \right. \end{equation*}

Constraints

* $0 \leq n \leq 44$

Input

An integer $n$ is given.

Example

Input

3


Output

3

### Response

```cpp
#include<iostream>
using namespace std;

int main(){
  int n;cin >> n;
  int dp[45];dp[0]=1;dp[1]=1;
  for(int i=2;i<45;i++){
    dp[i]=dp[i-1]+dp[i-2];
  }
  cout << dp[n] << endl;
}


```