#include<bits/stdc++.h>
using namespace std;

int main(){
	int n, F[45];
	cin >> n;
	
	F[0] = F[1] = 1;
	
	for(int i = 2 ; i <= n ; i++){
		F[i] = F[i - 1] + F[i - 2];
		}
	
	cout << F[n] << endl;
	
	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<bits/stdc++.h>
using namespace std;

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