#include <stdio.h>

int main(){
  int n, i;  
  int a[45] = {1,1};
  
  scanf("%d", &n);
  
  for(i=2; i<=n; i++)
    a[i] = a[i-1] + a[i-2];
  
  printf("%d\n", a[n]);
  
  return 0;
}
### Prompt

Create a solution in cpp for 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 <stdio.h>

int main(){
  int n, i;  
  int a[45] = {1,1};
  
  scanf("%d", &n);
  
  for(i=2; i<=n; i++)
    a[i] = a[i-1] + a[i-2];
  
  printf("%d\n", a[n]);
  
  return 0;
}
```