#include<stdio.h>

int main(){
  int i,n,F[50];
  scanf("%d",&n);
  
  F[0] = 1;
  F[1] = 1;
  for (i=2;i<=n;i++){
    F[i] = F[i-2] + F[i-1];
  }
  printf("%d\n",F[i-1]);
  return 0;

}
### Prompt

Develop a solution in Cpp to the problem described below:

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 i,n,F[50];
  scanf("%d",&n);
  
  F[0] = 1;
  F[1] = 1;
  for (i=2;i<=n;i++){
    F[i] = F[i-2] + F[i-1];
  }
  printf("%d\n",F[i-1]);
  return 0;

}
```