import sys

# sys.setrecursionlimit(200005)
# sys.set_int_max_str_digits(1000005)
int1 = lambda x: int(x)-1
pDB = lambda *x: print(*x, end="\n", file=sys.stderr)
p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr)
def II(): return int(sys.stdin.readline())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LLI1(rows_number): return [LI1() for _ in range(rows_number)]
def SI(): return sys.stdin.readline().rstrip()

dij = [(0, 1), (-1, 0), (0, -1), (1, 0)]
# dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)]
inf = (1 << 63)-1
# md = 10**9+7
md = 998244353

def ok():
    n = II()
    s = list(SI())
    if s[0] == "a" or s[0] == "o": return False
    if s[-1] == "w": return False
    for c in s:
        if c not in "waon?":
            return False
    for i in range(n-1):
        if s[i]=="w":
            if s[i+1]=="?":
                s[i+1]="a"
            elif s[i+1] not in "ao":
                return False
    for i in range(n-1):
        if s[i+1] in "ao" and s[i]!="w" and s[i]!="?":
            return False
    return True

print("Yes" if ok() else "No")