*************************
Problem J - Game of Nines
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You are playing a simple game of adding digits. You are given a list of single
digits between 0 and 8 (inclusive).

In each move, you may choose any two digits **a** and **b**, add **a** to
**b**, and replace **b** with the sum **a + b**. If **a + b ≥ 10**, keep only
the units digit (e.g., 5 + 8 becomes 3; 4 + 6 becomes 0).

Whenever the sum is **9**, the result is eliminated immediately and cannot
participate in further additions. Note that you cannot add a digit to itself,
but you **may** choose two digits **a** and **b** that have the same value.

Your goal is to eliminate as many digits as possible, using any number of
moves.


Input
=====

The first line of input contains a single integer **n** (**2 ≤ n ≤ 1000**), the
number of digits.

Each of the next **n** lines contains a single digit between **0** and **8**,
forming the initial list of digits.


Output
======

Output a single integer — the **minimum number of digits** that will remain if
you play optimally to eliminate as many digits as possible.


Explanation of Sample Case 1
============================

Add **3** to **6** and eliminate one digit (3 + 6 becomes 9). The remaining
digits are **2** and **3**.

Then add **2** to **3** three times:

* 3 + 2 → 5
* 5 + 2 → 7
* 7 + 2 → 9 (eliminated)

The single digit remaining is **2**. It is also possible to eliminate two
digits with a different sequence of moves.


Sample Input 1
==============

::

  3
  2
  3
  6

Sample Output 1
===============

::

  1


Sample Input 2
==============

::

  2
  4
  4

Sample Output 2
===============

::

  2