title: Finding the the largest number in a list that its modulo with a given number is 0
body: <p>I need to define a recursive function that receives a list of
  non-negative integers <code>numbers</code>, and a positive integer <code>m</code>, and returns the largest number from the list that divides by m with no remainder. </p>
  
  <p>I can't use loops or python's max function on a list.</p>
  
  <p>I tried:</p>
  
  <pre><code>def find_max_mod(numbers, m):
      mx  = 1
      mxn = -1
      if len(numbers) == 1 and numbers[0] % m == 0:
          if mx &gt; numbers[0]:
              mx = numbers[0]
              return mx
      if len(numbers) == 1 and numbers[0] % m != 0:
          return -1
      elif len(numbers) == 0:
          return -1
      elif numbers[-1] % m == 0 and numbers[-1] &gt; mx:
          mx = numbers[-1]
      numbers = find_max_modulo(numbers[:-1], m)
  
      return mx
  </code></pre>
  
  <p>I can't figure how to save my largest number. Every recursive cycle it over-write on my <code>mx</code> number.</p>
  
  <p>I think I have a problem with the base condition but it is the smallest problem.</p>