new_contents: from time import time
  from math import pow, sqrt
  
  
  LIMIT = 1000
  PERIMETERS = [[0 for i in range(j)] for j in range(LIMIT/2)]
  
  
  def most_common(lst):
      return max(set(lst), key=lst.count)
  
  
  def main():
      for a in range(1, LIMIT/2):
          for b in range(a+1, LIMIT/2):
              c = sqrt(pow(a, 2) + pow(b, 2))  # Pythagorean theorem
              perimeter = a + b + c
              if c.is_integer() and perimeter < LIMIT:
                  PERIMETERS[b][a] = perimeter
      print 'Maximum perimeter options:', most_common([item for sublist in PERIMETERS for item in sublist if item])
  
  
  if __name__ == '__main__':
      t = time()
      main()
      print 'Time:', time() - t
  
subject: Add problem 39, right triangle perimeter options