
#include<iostream>

using namespace std;

int main()
{
	int n,i;
	int a[44];
	cin >> n;
	a[0]=1;
	a[1]=1;
	a[2]=2;
	for(i=2;i<=n;i++){
		a[i]=a[i-1]+a[i-2];
	}
	cout << a[n] << endl;
}
### Prompt

Please formulate 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,i;
	int a[44];
	cin >> n;
	a[0]=1;
	a[1]=1;
	a[2]=2;
	for(i=2;i<=n;i++){
		a[i]=a[i-1]+a[i-2];
	}
	cout << a[n] << endl;
}
```