using System;

using System.Collections.Generic;

public class Program

{

    public class Node{

        public int data;

        public Node next;

        public Node(int data, Node next = null){

            this.data = data;

            this.next = next;

        }

    }

    public static void Main()

    {

        var node = new Node(1,new Node(3,new Node(7,new Node(3,new Node(3,new Node(6,new Node(5,new Node(3,new Node(3)))))))));

        var result = KthToLast(node, 56);

        Console.WriteLine(result);

    }

    public static int KthToLast(Node root, int k){

        if(root == null)

            return -1;

        var set = new HashSet<int>();

        var curr = root;

        Node last = null;

        var len = 0;

        while(curr != null){

            len++;

            last = curr;

            curr = curr.next;

        }

        if(k == len)

            return root.data;

        if(k == 1)

            return last.data;

        k %= len;

        int count = len - k;

        curr = root;

        while(curr != null){

            if(count == 0){

                return curr.data;

            }

            count--;

            curr = curr.next;

        }

        return root.data;

    }

}