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 Kotlin (judge verdict: Accepted)

fun main(args: Array<String>) = p34()

fun p34() {
    val n = readLine()!!.toInt()

    val dp = LongArray(45)
    dp[0] = 1
    dp[1] = 1

    for (i in 2..n) dp[i] = dp[i - 1] + dp[i - 2]

    val answer = dp[n]

    println(answer)
}