N=int(input())

S=input().strip()

w=0
q=0
for s in S:
    if s=="?":
        if w==0:
            q=1
        w=0
        continue
    if s=="w":
        if w==0:
            w=1
            q=0
            continue
    if s in ["a","o"]:
        if w or q:
            w=0
            q=0
            continue
    if s=="n":
        if w==0:continue
    print("No")
    exit()
print("Yes")