N = int(input())
S = input()
ans = 'Yes'
for i in range(N):
  s = S[i]
  if s == 'w':
    if i == N - 1:
      ans = 'No'
      break
    if S[i+1] == 'o':
      continue
    elif S[i+1] == 'a':
      continue
    elif S[i+1] == '?':
      continue
    else:
      ans = 'No'
      break
  elif s == 'o':
    if i == 0:
      ans = 'No'
      break
    if S[i-1] == 'w':
      continue
    elif S[i-1] == '?':
      continue
    else:
      ans = 'No'
      break
  elif s == 'a':
    if i == 0:
      ans = 'No'
      break
    if S[i-1] == 'w':
      continue
    elif S[i-1] == '?':
      continue
    else:
      ans = 'No'
      break
  elif s == '?':
    continue
  elif s == 'n':
    continue
  else:
    ans = 'No'
    continue
print(ans)