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: Accepted)

using System;

namespace ALDS1_10_A {
    class Program {
        static void Main(string[] args) {
            Console.WriteLine(Fib(int.Parse(Console.ReadLine())));
        }

        static int Fib(int n) {
            if (n == 0 || n == 1)
                return 1;
            int[] fib = new int[n + 1];
            fib[0] = fib[1] = 1;
            for (int i = 2; i <= n; i++) {
                fib[i] = fib[i - 1] + fib[i - 2];
            }
            return fib[n];
        }
    }
}