#include <iostream>
using namespace	std;
int main(){

  int n,a[45],i;

  cin>>n;
  a[0]=1;
  a[1]=1;

  for(i=2;i<=n;i++) a[i]=a[i-2]+a[i-1];

  cout<<a[n]<<endl;

  return 0;

}
### Prompt

Generate 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 main(){

  int n,a[45],i;

  cin>>n;
  a[0]=1;
  a[1]=1;

  for(i=2;i<=n;i++) a[i]=a[i-2]+a[i-1];

  cout<<a[n]<<endl;

  return 0;

}
```