import java.util.*;

public class LinkedList {
    public Node head;
    public Node tail;

    public LinkedList() {
        head = null;
        tail = null;
    }

    public int[] toArray() {
        int count = this.count();
        int[] arr = new int[count];
        Node node = this.head;
        for (int i = 0; i < arr.length; i++) {
            arr[i] = node.value;
            node = node.next;
        }
        return arr;
    }

    public void addInTail(Node item) {
        if (this.head == null)
            this.head = item;
        else
            this.tail.next = item;
        this.tail = item;
    }

    public Node find(int value) {
        Node node = this.head;
        while (node != null) {
            if (node.value == value)
                return node;
            node = node.next;
        }
        return null;
    }

    public ArrayList<Node> findAll(int _value) {
        ArrayList<Node> nodes = new ArrayList<>();
        Node node = this.head;
        while (node != null) {
            if (node.value == _value) {
                nodes.add(node);
            }
            node = node.next;
        }

        return nodes;
    }

    public boolean remove(int _value) {
        if (this.head == null) {
            return false;
        }

        Node node = this.head;
        Node prevNode = null;

        boolean isNodeFound = false;
        while (node != null) {
            if (node.value == _value) {
                isNodeFound = true;
                break;
            }

            prevNode = node;
            node = node.next;
        }

        if (isNodeFound) {
            if (node == tail) {
                tail = prevNode;
            }

            if (node == head) {
                head = node.next;
            }

            if (prevNode != null) {
                prevNode.next = node.next;
            }
            node = null;
        }

        return isNodeFound;
    }

    public void removeAll(int _value) {

        if (this.head == null) {
            return;
        }

        Node node = this.head;
        Node prevNode = null;

        while (node != null) {
            if (node.value == _value) {
                if (node == this.head) {
                    this.head = node.next;
                }

                if (node == this.tail) {
                    this.tail = prevNode;
                }

                if (prevNode != null) {
                    prevNode.next = node.next;
                    node = prevNode;
                }
            }
            prevNode = node;
            node = node.next;
        }
    }

    public void clear() {
        this.head = null;
        this.tail = null;
    }

    public int count() {
        Node node = this.head;
        int cnt = 0;

        if (node != null) {
            while (node != null) {
                cnt++;
                node = node.next;
            }
        }
        return cnt;
    }

    public void insertAfter(Node _nodeAfter, Node _nodeToInsert) {
        if (this.head == null || _nodeAfter == this.tail) {
            addInTail(_nodeToInsert);
        } else if (_nodeAfter == null) {
            _nodeToInsert.next = this.head;
            this.head = _nodeToInsert;
        } else {
            _nodeToInsert.next = _nodeAfter.next;
            _nodeAfter.next = _nodeToInsert;
        }
    }

}

class Node {
    public int value;
    public Node next;

    public Node(int _value) {
        value = _value;
        next = null;
    }
}