N = int(input())
S = input()
for c in S:
    if c not in 'waon?':
        exit(print('No'))
if 'wn' in S or 'na' in S or 'no' in S:
    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 T[0]=='a' or T[-1]=='w':
    exit(print('No'))

T = T.replace('?a','').replace('w?','')
print('Yes'if  all(c=='?' for c in T) else 'No')