static ArrayList<Integer> find_intersection(ArrayList<Integer> arr1, ArrayList<Integer> arr2, ArrayList<Integer> arr3)
    {
        // Write your code here.
        ArrayList<Integer> result = new ArrayList<Integer>();
        int n1 = arr1.size(), n2 = arr2.size(), n3 = arr3.size();
        int i = 0, j = 0, k = 0;
        while (i < n1 & j < n2 && k < n3) {
            if (arr1.get(i).equals(arr2.get(j)) && arr2.get(j).equals(arr3.get(k))) {
                result.add(arr1.get(i));
                i++; j++; k++;
            } else {
                int min = Math.min(arr1.get(i), Math.min(arr2.get(j), arr3.get(k)));
                if (arr1.get(i) == min) i++;
                if (arr2.get(j) == min) j++;
                if (arr3.get(k) == min) k++;
            }
        }

        if (result.isEmpty()) {
            return new ArrayList<Integer>(Arrays.asList(-1));
        }

        return result;
    }