Problem:
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Fibonacci Number

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*}

Input

An integer $n$ is given.

output

Print the $n$-th fibonacci number in a line.

Constraints

$0 \leq n \leq 44$

Sample Input 1

3

Sample Output 1

3

Solution in C++ (judge verdict: Time Limit Exceeded)

#include <iostream>
using namespace std;

int Fibonacci(int n)
{
	if(n == 0){
		return 1;
	}else if(n == 1){
		return 1;
	}else{
		return Fibonacci(n-1) + Fibonacci(n-2);
	}
}

int main()
{
	int n;
	cin >> n;
	cout << Fibonacci(n) << endl;
	return 0;
}