[ 'A',
  'AA',
  'AAA',
  'AAAA',
  'AAAAA',
  'AAAAAA',
  'AAAAAAA',
  'AAAAAAAA',
  'AAAAAAAAA',
  'AAAAAAAAAA',
  'AAAAAAAAAAA',
  'AAAAAAAAAAAA',
  'AAAAAAAAAAAAA',
  'AAAAAAAAAAAAAA',
  'AAAAAAAAAAAAAAA',
  'AAAAAAAAAAAAAAAA',
  'AAAAAAAAAAAAAAAAA',
  'AAAAAAAAAAAAAAAAAA',
  'AAAAAAAAAAAAAAAAAAA',
  'AAAAAAAAAAAAAAAAAAAA' ]
0