EMPTY="."
FULL="O"


class Piece:
	def __init__(self,variants):
		self.variants=variants


pieces=[]

pieces.append(Piece([
	# OO
	# OO
	((0,0),(0,1),(1,0),(1,1))
]))

pieces.append(Piece([
	# OOOO
	((0,0),(0,1),(0,2),(0,3)),
	((0,0),(1,0),(2,0),(3,0))
]))

pieces.append(Piece([
	# OOO
	# .O.
	((0,0),(0,1),(0,2),(1,1)),
	((0,0),(1,0),(2,0),(1,1)),
	((0,0),(1,-1),(1,0),(1,1)),
	((0,0),(1,-1),(1,0),(2,0))
]))

pieces.append(Piece([
	# .OO
	# OO.
	((0,0),(0,1),(1,-1),(1,0)),
	((0,0),(1,0),(1,1),(2,1)),

	# OO.
	# .OO
	((0,0),(0,1),(1,1),(1,2)),
	((0,0),(1,0),(1,-1),(2,-1))
]))

pieces.append(Piece([
	# OOO
	# O..
	((0,0),(1,0),(0,1),(0,2)),
	((0,0),(1,0),(2,0),(2,1)),
	((0,0),(1,-2),(1,-1),(1,0)),
	((0,0),(0,1),(1,1),(2,1)),

	# OOO
	# ..O
	((0,0),(0,1),(0,2),(1,2)),
	((0,0),(0,1),(1,0),(2,0)),
	((0,0),(1,0),(1,1),(1,2)),
	((0,0),(1,0),(2,0),(2,-1))
]))

WIDTH=5
HEIGHT=5
board=[[EMPTY]*WIDTH for r in range(HEIGHT)]


def fill(board):
	point=firstEmpty(board)
	if not point: return True
	res=[]
	for p in pieces:
		for v in p.variants:
			if place(board,point,v):
				partialRes=fill(board)
				if partialRes:
					res+=[((point,v), partialRes)]
				remove(board,point,v)
	return res


def firstEmpty(board):
	for (r,row) in enumerate(board):
		for (c,cell) in enumerate(row):
			if cell==EMPTY:
				return (r,c)
	return None


def place(board,point,piece):
	(r,c)=point
	if not all(0<=r+ri<HEIGHT and 0<=c+ci<WIDTH and board[r+ri][c+ci]==EMPTY for (ri,ci) in piece):
		return False
	for (ri,ci) in piece:
		board[r+ri][c+ci]=FULL
	return True


def remove(board,point,piece):
	(r,c)=point
	for (ri,ci) in piece:
		board[r+ri][c+ci]=EMPTY


def visualise(board,tree,letter="A"):
	if tree is True:
		for row in board:
			print("".join(row))
		print()
		return
	for (((r,c),piece),rest) in tree:
		for (ri,ci) in piece:
			board[r+ri][c+ci]=letter
		visualise(board,rest,chr(ord(letter)+1))


res=fill(board)
if res:
	visualise(board,res)
else:
	print(res)