N = int(input())
S = list(input())
def hantei():
    i = 0
    while i < N:
        if S[i] == 'n':
            i += 1
        elif S[i] == 'w':
            if i == N-1:
                return False
            elif S[i+1] == 'a' or S[i+1] == 'o' or S[i+1] == '?':
                i += 2
            else:
                return False
        elif S[i] == '?':
            if i == N-1:
                i += 1
            elif S[i+1] == 'a' or S[i+1] == 'o':
                i += 2
            else:
                i += 1
        else:
            return False
    return True

if hantei():
    print('Yes')
else:
    print('No')