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 Java (OpenJDK 11.0.6) (judge verdict: Wrong Answer)

import java.util.ArrayList;
import java.util.Scanner;

/*
問題文

*/

public class Main {
    public static void main(String[] args){

        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        long k = sc.nextLong();
        int[] a = new int[n];

        for (int i = 0; i < n; i++) {
            a[i] = sc.nextInt();
        }

        ArrayList<Integer> list = new ArrayList<Integer>();
        list.add(1);
        // ループの先頭の町がリストの何番目にあるかを格納する変数
        int check = 0;


        // ひとつめの町の転送先
        int temp = 1;
        for (int i = 0; i <= n; i++) {

        	temp = a[temp-1];
            // 訪れた町かチェック
            // 訪れていた場合、ループ前のイントロ部分の長さを求める
            if (list.contains(temp)) {
                check = list.indexOf(temp);
            	break;
            }
            list.add(temp);
        }

        // ループが存在しない場合
        if ((long)list.size() == k){
            System.out.println(temp);
        } else {
            int std = (int)((k-check) % (list.size() - check));

            System.out.println(list.get(std + check));
        }
    }
}