n=int(input())
s=list(input())[::-1]

cnt=10**6
while 1<len(s):
  cnt-=1
  if cnt==0:exit(print("No"))
  x="".join(s[-2:])[::-1]
  if x=="??":
    s.pop()
  elif x=="wa" or x=="wo" or x=="w?" or x=="?a" or x=="?o" or x=="?n":
    s.pop()
    s.pop()
  elif x[0]=="n":
    s.pop()
  print(s,x)
if s==[] or s==["?"] or s==["n"]:
  print("Yes")
else:
  print("No")