N = int(input())
S = input()
i = 0
while i<N:
    if i+1<N and S[i]=="w" and (S[i+1]=="a" or S[i+1]=="o" or S[i+1]=="?"):
        i+=2
    elif S[i]=="n":
        i+=1
    elif i+1<N and S[i]=="?" and (S[i+1]=="a" or S[i+1]=="o"):
        i+=2
    elif S[i]=="?":
        i+=1
    else:
        print("No")
        exit()
print("Yes")