diff --git a/tetris.py b/tetris.py
new file mode 100644
--- /dev/null
+++ b/tetris.py
@@ -0,0 +1,119 @@
+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)