text: 
  
  def count_bases(dna):
  
      a_count = 0
      c_count = 0
      g_count = 0
      t_count = 0
  
      for base in dna:
          if base == 'a':
              a_count = a_count + 1
          elif base == 'c':
              c_count = c_count + 1
          elif base == 'g':
              g_count = g_count + 1
          elif base == 't':
              t_count = t_count + 1
          else:
              raise Exception("DNA should consist of A, C, G and T bases. Found: {}".format(base))
  
      return a_count, c_count, g_count, t_count
  
  
  if __name__ == '__main__':
      dna = input("Enter a DNA base string:\n").lower()
      a_count, c_count, g_count, t_count = count_bases(dna)
  
      print(a_count)
      print(c_count)
      print(g_count)
      print(t_count)
  
  
  
  