import java.util.*;

public class LinkedIntList {
	private ListNode front;
	
	public LinkedIntList() {
		front = null;
	}
	
	// Removes and returns the first value.
	// Throws a NoSuchElementException on empty list.
	public int remove() {
		if (front == null) {
			throw new NoSuchElementException();
		} else {
			int result = front.data;
			front = front.next;
			return result;
		}
	}

	// Removes value at given index from list.
	// Precondition: 0 <= index < size()
	public void remove(int index) {
		if (index == 0) {
			// special case: removing first element
			front = front.next;
		} else {
			// removing from elsewhere in the list
			ListNode current = front;
			for (int i = 0; i < index - 1; i++) {
				current = current.next;
			}
			current.next = current.next.next;
		}
	}

	// Adds given value to list in sorted order.
	// Precondition: Existing elements are sorted
	public void addSorted(int value) {
		if (front == null || value <= front.data) {
			// insert at front of list
			front = new ListNode(value, front);
		} else {
			// insert in middle of list
			ListNode current = front;
			while (current.next != null && current.next.data < value) {
				current = current.next;
			}
			current.next = new ListNode(value, current.next);
		}
	}
	
	// Gets the item in the list at the given index
	public int get(int index) {
		ListNode current = front;
		for (int i = 0; i < index; i++) {
			current = current.next;
		}
		return current.data;
	}

	// Adds the given value to the end of the list
	public void add(int value) {
		if (front == null) {
			front = new ListNode(value);
		} else {
			ListNode current = front;
		
			// find the last node of the list
			while (current.next != null) {
				current = current.next;
			}
		
			current.next = new ListNode(value);
		}
	}
	
	// Returns a String representation of this list
	public String toString() {
   	if (front == null)
   		return "[]";
   	else {
        	String result = "[" + front.data;
         ListNode current = front.next;
         while (current != null) {
         	result += ", " + current.data;
         	current = current.next;
         }
         result += "]";
         return result;
     	}
	}
}