#include<stdio.h>
int main(void)
{
	int dp[1000]={0};
	int n,i;

	scanf("%d",&n);
	dp[0]=1;
	dp[1]=1;
	for(i=2;i!=n+1;i++){
		dp[i]=dp[i-1]+dp[i-2];
	}
	printf("%d\n",dp[n]);
}
### 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<stdio.h>
int main(void)
{
	int dp[1000]={0};
	int n,i;

	scanf("%d",&n);
	dp[0]=1;
	dp[1]=1;
	for(i=2;i!=n+1;i++){
		dp[i]=dp[i-1]+dp[i-2];
	}
	printf("%d\n",dp[n]);
}
```