#include<bits/stdc++.h>
#define int long long
using namespace std;
 
signed main(){
	vector<int>a(45);
	a[0]=a[1]=1;
	for(int b=2;b<45;b++)a[b]=a[b-1]+a[b-2];
	int c;
	cin>>c;
	cout<<a[c]<<endl;
}
### Prompt

Your task is to create 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<bits/stdc++.h>
#define int long long
using namespace std;
 
signed main(){
	vector<int>a(45);
	a[0]=a[1]=1;
	for(int b=2;b<45;b++)a[b]=a[b-1]+a[b-2];
	int c;
	cin>>c;
	cout<<a[c]<<endl;
}
```