new_contents: # Author: Param Singh <paramsingh258@gmail.com>
  # Cracking the code
  
  i, k, s = map(int, raw_input().split())
  ai, bi = map(int, raw_input().split())
  diff = k - i
  v = diff / 2
  if diff % 2 == 0:
      val = (2 ** (4*v-s)) * (ai + bi)
  else:
      val = (2 ** (4*v - s + 1.5) * (ai + (3 ** 0.5) * bi))
  print "%f" % val
  
subject: Solve Cracking the code