#include <bits/stdc++.h>
using namespace std;
int main() {
  int fib[100];
  fib[0] = 1;
  fib[1] = 1;
  for(int i = 2;i < 50;i++)fib[i] = fib[i-1] + fib[i-2];
  int n;
  cin >> n;
  cout << fib[n] << endl;
}


### Prompt

In Cpp, your task is to solve 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>
using namespace std;
int main() {
  int fib[100];
  fib[0] = 1;
  fib[1] = 1;
  for(int i = 2;i < 50;i++)fib[i] = fib[i-1] + fib[i-2];
  int n;
  cin >> n;
  cout << fib[n] << endl;
}


```