Problem:
Score: 400 points

Problem Statement

The Kingdom of Takahashi has N towns, numbered 1 through N.

There is one teleporter in each town. The teleporter in Town i (1 \leq i \leq N) sends you to Town A_i.

Takahashi, the king, loves the positive integer K. The selfish king wonders what town he will be in if he starts at Town 1 and uses a teleporter exactly K times from there.

Help the king by writing a program that answers this question.

Constraints

2 \leq N \leq 2 \times 10^5

1 \leq A_i \leq N

1 \leq K \leq 10^{18}

Input

Input is given from Standard Input in the following format:

N K
A_1 A_2 \dots A_N

Output

Print the integer representing the town the king will be in if he starts at Town 1 and uses a teleporter exactly K times from there.

Sample Input 1

4 5
3 2 4 1

Sample Output 1

4

If we start at Town 1 and use the teleporter 5 times, our travel will be as follows: 1 \to 3 \to 4 \to 1 \to 3 \to 4.

Sample Input 2

6 727202214173249351
6 5 2 5 3 2

Sample Output 2

2

Solution in Kotlin (1.3.71) (judge verdict: Runtime Error)

import java.util.*

fun main(args: Array<String>) {
    val sc = Scanner(System.`in`)
    val n = sc.nextInt()
    val k = sc.nextLong()
    val a = (0 until n).map { sc.next().toInt() }
    println(problem167d(n, k, a))
}

fun problem167d(n: Int, k: Long, a: List<Int>): Int {
    val visited = hashMapOf<Int, Int>()
    visited[1] = 1
    var loopPoint = -1 to -1
    var current = 1
    for (i in 0 until n) {
        val next = a[current - 1]
        if (i.toLong() >= k - 1) {
            return next
        }
        if (visited.contains(next)) {
            loopPoint = next to i + 1 - visited[next]!!
            break
        }
        visited[next] = i + 1
        current = next
    }

    val loopIndex = (k - visited[loopPoint.first]!!) % loopPoint.second
    current = loopPoint.first
    for (i in 0 until loopIndex) {
        current = a[current - 1]
    }
    return current
}