n=int(input())
s=list(input())
s.reverse()
while len(s):
    if len(s)>1 and ("".join(s[len(s)-2:])=="aw" or "".join(s[len(s)-2:])=="ow" or "".join(s[len(s)-2:])=="?w"):
        for i in range(2):s.pop()
    elif s[-1]=="n":s.pop()
    elif s[-1]=="?":
        if len(s)>1 and (s[-2]=="o"or s[-2]=="a"):
            for i in range(2):s.pop()
        else:s.pop()
    else:
        print("No")
        exit()
print("Yes")