N = int(input())
if (N == 1):
  print('a')
  exit()
elif (N == 2):
  print('aa')
  print('ab')
  exit()
elif (N == 3):
  print('aaa')
  print('aab')
  print('aba')
  print('abb')
  exit()
elif (N == 4):
  print('aaaa')
  print('aaab')
  print('aaba')
  print('aabb')
  print('abaa')
  print('abab')
  print('abbb')
  exit()