Remove one ListofList from another listofLists Java

Question

I have two listsOfList

List<ArrayList<String>> listOfLists1 = new ArrayList<ArrayList<String>>();
List<ArrayList<String>> listOfLists2 = new ArrayList<ArrayList<String>>();

listOfLists1 = [[s1,c1],[s1,c2],[s2,c1]];
listOfLists2 = [[s2,c1]];

Now I want to remove listOfLists2 from listOfLists1 so that the result is result = [[s1,c1],[s1,c2]]

I have tried this so far but still

List<ArrayList<String>> listofLists1 = new ArrayList<ArrayList<String>>();
List<ArrayList<String>> listofLists2 = new ArrayList<ArrayList<String>>();

ArrayList<String> list1 = new ArrayList<String>();
list1.add("s1");
list1.add("c1");
listofLists1.add(list1);

ArrayList<String> list2 = new ArrayList<String>();
list2.add("s1");
list2.add("c2");
listofLists1.add(list2);

ArrayList<String> list3 = new ArrayList<String>();
list3.add("s2");
list3.add("c1");
listofLists1.add(list3);

ArrayList<String> list4 = new ArrayList<String>();
list4.add("s1");
list4.add("c1");
listofLists2.add(list4);

ArrayList<String> list5 = new ArrayList<String>();
list4.add("s1");
list4.add("c2");
listofLists2.add(list4);

listofLists1.removeAll(listofLists2);

Now still when I print listofLists1 I get all the values that is [[s1,c1],[s1,c2],[s2,c1]];