import sys

# sys.setrecursionlimit(200005)
# sys.set_int_max_str_digits(200005)
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-(-1 << 31)
inf = -1-(-1 << 62)

# md = 10**9+7
md = 998244353

# from random import randrange
#
# loop=20
# n=II()
# aa=[randrange(2) for _ in range(n)]
# print(*aa)
#
# for _ in range(loop):
#     na=[0]*n
#     for i in range(n):
#         na[i]=(aa[i-1]&(aa[i]^1))|(aa[i]&aa[(i+1)%n])
#     aa=na
#     print(*aa)

n = II()
aa = LI()
ans = 0
for i in range(n): ans += aa[i-1]*(1-aa[i])
ans = pow(n, md-2, md)*ans%md
print(ans)