n=int(input())

for i in range(n):
  c='A'
  for j in range(0,i+1):
    print(c,end="")
    c=chr(ord(c)+1)
  print()
  

/**************************************************************
	Problem: 1976
	User: admin
	Language: Python
	Result: Accepted
	Time:92 ms
	Memory:34244 kb
****************************************************************/