Problem:
MathJax.Hub.Config({ tex2jax: { inlineMath: [["$","$"], ["\\(","\\)"]], processEscapes: true }});

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<stdio.h>

int fib(int n){
    if( n==0 || n==1) return 1;
    n = fib(n-1)+fib(n-2);
    return n;
}
int main(){
    int n;
    scanf("%d",&n);
    n = fib(n);
    printf("%d\n",n);
    return 0; 
}