n = int(input())
s = input()

i = 0
while i < n:
    if s[i:i+2] == "w?" or s[i:i+2] == "?a" or s[i:i+2] == "?o" or s[i:i+2] == "wa" or s[i:i+2] == "wo":
        i += 2
    elif s[i] == "n" or s[i] == "?":
        i += 1
    else:
        print("No")
        break

if i == n:
    print("Yes")