Accessing ArrayList Elements (Integer / String) And Put Them Into Hashtable

I have a data structure such as: ArrayList<ArrayList<Integer,String>

The data looks as [[1,2,3] [3,4] [99,98,40,32,45,65,1]]

I am trying to access each element and put them into a hashtable such as:

Hashtable<Integer,String>

With what I am doing below I am getting an out of bound error but can't see any other way of accessing the element

public static void hash(ArrayList<ArrayList<String>> list)
{
for(int i = 0; i < list.size(); i++)
{
int cnt = 0;
for(int y = 0; y < list.size(); y++)
{
if (! hashMap.containsValue(list.get(i).get(y)))
{
hashMap.put(cnt, list.get(i).get(y));
cnt++;
}
...