unknown run-time exception in kattis problem "marbles on a tree" - graph

Question

I've been trying to implement this solution (https://algorithmist.com/wiki/UVa_10672_-_Marbles_on_a_tree) to this kattis problem (https://open.kattis.com/problems/marblestree). This is a graph theory problem involving a tree and a greedy algorithm similar to DFS. My code works for the sample test case, but generates a run-time exception on the second test case. The problem is, I have no idea where the exception is happening or what the exception is - Kattis gives me no hints. This isn't a memory exceeded or time exceeded deal, as kattis has a seperate notification for those errors; something somewhere is generating an explicit run-time exception and I have no idea where. My guess is that the exception is happening somewhere in the while loop with the condition "que.size() > 0", but I cant find where. Here is the code:
import java.util.*;
import java.io.*;
public class marblestree
{
public static ArrayList<ArrayList<Integer>> adjList = new ArrayList<>();
public static ArrayList<Integer> values = new ArrayList<>();
public static ArrayList<Integer> leaves = new ArrayList<>();
public static void main(String args[]) throws IOException
{
Scanner in = new Scanner(System.in);
int n = 1;
while (n > 0)
{
n = in.nextInt();
if (n == 0)
break;
for (int i = 0; i < n; i++)
{
adjList.add(new ArrayList<Integer>());
}
for (int j = 0; j < n; j++)
{
in.nextInt();
values.add(in.nextInt());
int adjNum = in.nextInt();
for (int m = 0; m < adjNum; m++)
{
adjList.get(in.nextInt() - 1).add(j);
}
if (adjNum == 0)
leaves.add(j);
}
//System.out.println("adjList: " + adjList);
//handle case
LinkedList<Integer> que = new LinkedList<>();
for (Integer y : leaves)
{
que.add(y);
}
int moves = 0;
adjList.get(0).add(0);
while (que.size() > 0)
{
//System.out.println("next, this is currently the que: " + que);
//System.out.println("and these are the values at each vertex:" + values);
int now = que.poll();
if (now != 0)
{
if (adjList.get(now).get(0) > 0 && !que.contains(adjList.get(now).get(0)))
que.add(adjList.get(now).get(0));
moves += Math.abs(values.get(now) - 1);
values.set(adjList.get(now).get(0), values.get(adjList.get(now).get(0)) + (values.get(now) - 1));
values.set(now, 1);
}
}
System.out.println(moves);
adjList = new ArrayList<>();
values = new ArrayList<>();
leaves = new ArrayList<>();
}
}
}