dp = [1, 0]
input()
for c in input():
    ndp = [0, 0]
    if c == 'w' or c == '?':
        ndp[1] |= dp[0]
    if c == 'a' or c == 'o' or c == '?':
        ndp[0] |= dp[1]
    if c == 'n' or c == '?':
        ndp[0] |= dp[0]
    dp = ndp
print('Yes' if dp[0] else 'No')