N = int(input())
S = input()
for c in S:
    if c not in 'waon?':
        exit(print('No'))

T = S.replace('n','').replace('wa','').replace('wo','')
if T=='':
    exit(print('Yes'))

T = T.replace('o','a')
assert all(c in 'wa?' for c in T)

if len(T) == 1:
    exit(print('Yes' if T=='?' else 'No'))

buf = ''
for c in T:
    if c == 'w':
        if buf=='w' or buf=='a':
            exit(print('No'))
        buf = 'w'
    elif c == 'a':
        if buf=='a' or buf=='':
            exit(print('No'))
        buf = ''
    else:
        if buf=='w':
            buf = ''
        elif buf=='a':
            assert False
        else:
            buf = '?'
if buf=='w':
    print('No')
else:
    print('Yes')