package main

import . "fmt"
import . "strings"

func main() {
	var n,s string 
	Scan(&n,&s)
	s=ReplaceAll(s,"wa","n")
	s=ReplaceAll(s,"wo","n")
	s=ReplaceAll(s,"w?","n")
	s=ReplaceAll(s,"?a","n")
	s=ReplaceAll(s,"?o","n")
	s=ReplaceAll(s,"?","")
	s=ReplaceAll(s,"n","")
	if len(s)==0 {
		Println("Yes")
	} else {
		Println("No")
	}
}