#include <bits/stdc++.h>
using namespace std;
int main() {
    vector<int> F(100);
	int n;
	cin>>n;
	F[0]=1;
	F[1]=1;
	for(int i=2;i<=n;i++){
	    F[i]=F[i-2]+F[i-1];
	}
	cout<<F[n]<<'\n';
	return 0;       
}

### Prompt

Construct a Cpp code solution to the problem outlined:

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() {
    vector<int> F(100);
	int n;
	cin>>n;
	F[0]=1;
	F[1]=1;
	for(int i=2;i<=n;i++){
	    F[i]=F[i-2]+F[i-1];
	}
	cout<<F[n]<<'\n';
	return 0;       
}

```