public static int lilysHomework(List<Integer> arr) {
        List<Integer> ascendingSorted = new ArrayList<>(arr);
        List<Integer> descendingSorted = new ArrayList<>(arr);
        Collections.sort(ascendingSorted);
        Collections.sort(descendingSorted, (a,b) -> (b - a));
        
        if(arr.equals(ascendingSorted) || arr.equals(descendingSorted))
            return 0;
            
        List<Integer> ascendingList = new ArrayList<>(arr);
        List<Integer> descendingList = new ArrayList<>(arr);
        
        Map<Integer, Integer> ascendingIdxMap = new HashMap<>();
        Map<Integer, Integer> descendingIdxMap = new HashMap<>();
        for(int i = 0; i < arr.size(); i++){
            ascendingIdxMap.put(ascendingSorted.get(i), i);
            descendingIdxMap.put(descendingSorted.get(i), i);
        }
        int ascCount = 0, desCount = 0;
        for(int i = 0; i < arr.size(); i++){
            if(ascendingList.get(i) != ascendingSorted.get(i)){
                int tmp = ascendingList.get(i);
                int idx = ascendingIdxMap.get(ascendingList.get(i));
                ascendingList.set(idx, tmp);
                ascCount++;
            }                
            if(descendingList.get(i) != descendingSorted.get(i)){
                int tmp = descendingList.get(i);
                int idx = descendingIdxMap.get(descendingList.get(i));
                descendingList.set(idx, tmp);
                desCount++;
            }                
        }
        return Math.min(ascCount, desCount);
    }