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