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

def is_wawon(s):
    if not s:
        return True
    if s[:2] == 'wa' or s[:2] == 'wo':
        return is_wawon(s[2:])
    if s[0] == 'n':
        return is_wawon(s[1:])
    return False

def solve(S):
    if '?' not in S:
        return is_wawon(S)
    for c in 'wan':
        if solve(S.replace('?', c, 1)):
            return True
    return False

print('Yes' if solve(S) else 'No')