N = int(input())
S = list(input())
S.reverse()
S.append("#")
for i in range(N):
    if S[i] == "n":
        continue
    elif S[i] == "a" or S[i] == "o":
        if S[i + 1] == "w" or S[i + 1] == "?":
            S[i + 1] = "n"
            continue
        else:
            print("No")
            exit()
    elif S[i] == "?":
        if S[i + 1] == "w":
            S[i + 1] = "n"
        continue
    else:
        print("No")
        exit()
        
print("Yes")