code: def findfactor(cp1, cp2):
      size = 2
  
      if len(cp1) % 2 != 0:
          raise error("Strings should be even-sized")
  
      if len(cp1) != len(cp2):
          raise error("Samples should be same size")
  
      sample_count = _sample_count(cp1, size)
  
      sum_ri_2 = _sum2(cp2, cp2, sample_count)
      sum_aij_ri = _sum2(cp1, cp2, sample_count)
  
      return sum_aij_ri / sum_ri_2
  
imports: import math
  import struct
  from ctypes import create_string_buffer
label_desc: Use image node_id 19 for calling a global function with example usage: findfactor(cp1, cp2) and returns: unknown