text: #!/usr/bin/env python3
  # -*- coding: utf-8 -*-
  
  if __name__ == "__main__":
      U = set("abcdefghijklmnopqrstuvwxyz")
      A = {'b', 'k', 'n', 'o', 'r'}
      B = {'a', 'b', 'k', 'u'}
      C = {'o', 'p'}
      D = {'a', 'm', 'n', 'y', 'z'}
  
      X = (A.union(B)).intersection(D)
      print(f'X= {X}')
  
      AA = U.difference(A)
  
      Y = (AA.intersection(D)).union(C.difference(B))
      print(f'Y = {Y}')
  