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;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ALDS1_10_A
{
    class Program
    {
        static void Main(string[] args)
        {
            Fibonacci fibonacci = new Fibonacci();
            Console.WriteLine(fibonacci.GetValue(int.Parse(Console.ReadLine())));
            //Console.ReadLine();
        }
    }

    class Fibonacci
    {
        int[] fibonacci;

        public Fibonacci()
        {
            this.fibonacci = new int[45];
            this.fibonacci[0] = 1;
            this.fibonacci[1] = 1;
        }

        public int GetValue(int index)
        {
            if (this.fibonacci[index] == 0)
            {
                this.fibonacci[index] = this.GetValue(index - 1) + this.GetValue(index - 2);
            }
            return this.fibonacci[index];
        }
    }
}