title: Find maximum and minimum value of a matrix
body: <p>I have this code wrote in python 3:</p>
  
  <pre><code>matrix = []
      loop = True
      while loop:
          line = input()
          if not line: 
              loop = False
          values = line.split()
          row = [int(value) for value in values]
          matrix.append(row)
  
      print('\n'.join([' '.join(map(str, row)) for row in matrix]))
      print('matrix saved')
  </code></pre>
  
  <p>an example of returned matrix would be [[1,2,4],[8,9,0]].Im wondering of how I could find the maximum and minimum value of a matrix? I tried the max(matrix) and min(matrix) built-in function of python but it doesnt work.</p>
  
  <p>Thanks for your help!</p>