#include <iostream>
using namespace std;

int S[50];

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

Your task is to create a CPP solution 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 S[50];

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