local n = io.read("*n", "*l")
local s = io.read()
-- w, aon
local a1, a2 = false, true
for i = 1, n do
  local t1, t2 = false, false
  local b = s:sub(i, i)
  if b == "w" then
    if a2 then
      t1 = true
    end
  elseif b == "a" or b == "o" then
    if a1 then
      t2 = true
    end
  elseif b == "n" then
    if a2 then
      t2 = true
    end
  elseif b == "?" then
    if a1 then
      t2 = true
    end
    if a2 then
      t1, t2 = true, true
    end
  else
    print("No") os.exit()
  end
  a1, a2 = t1, t2
end
print(a2 and "Yes" or "No")