n = int(input())
s = input()
s = s.replace("wa","")
s = s.replace("wo","")
s = s.replace("?a","")
s = s.replace("?o","")
s = s.replace("w?","")
s = s.replace("n","")
s = s.replace("?","")
if s == "":
	print("Yes")
else:
	print("No")