mod = 998244353
n = int(input())
p = list(map(int, input().split()))
q = [-1] * n
for i in range(n):
	q[p[i]] = i
l, r = n, -1
ans = 1
for i in range(n):
	if l <= q[i] <= r:
		ans *= r - l + 1 - i
		ans %= mod
	else:
		l = min(l, q[i])
		r = max(r, q[i])
print(ans)