#include <stdio.h>

int main()
{
    int i, n, F[50];
    F[0] = 1, F[1] = 1;
    scanf("%d", &n);
    for(i=2; i<=n; ++i)
        F[i] = F[i-1]+F[i-2];
    printf("%d\n", F[n]);
    return 0;
}

### 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 <stdio.h>

int main()
{
    int i, n, F[50];
    F[0] = 1, F[1] = 1;
    scanf("%d", &n);
    for(i=2; i<=n; ++i)
        F[i] = F[i-1]+F[i-2];
    printf("%d\n", F[n]);
    return 0;
}

```