s = [input() for i in range(3)]

mode = 1
for i in range(3):
	for j in range(2):
		if s[i][j] == s[i][j+1]:
			mode = 0

for i in range(2):
	for j in range(3):
		if s[i+1][j] == s[i][j]:
			mode = 0

if mode:
	print("Yes")
else:
	print("No")