N = int(input())
S = input()

S.replace("wa", "")
S.replace("wo", "")
S.replace("n", "")

S = list(S)
n = len(S)
i = 0
# ?は任意の文字を表す
while i < n:
    if (
        S[i] == "w"
        and S[i + 1] == "o"
        or S[i] == "?"
        and S[i + 1] == "o"
        or S[i] == "w"
        and S[i + 1] == "?"
        or S[i] == "?"
        and S[i + 1] == "?"
    ):
        i += 2
    elif S[i] == "w" and S[i + 1] == "a":
        i += 2
    elif S[i] == "n":
        i += 1
    else:
        print("No")
        exit()
print("Yes")