n = int(input())
A = list(map(int, input().split()))
mod = 998244353

I = [-1 for _ in range(n)]
for i in range(n):
    I[A[i]] = i
ans = 1
l, r = -1, -1
for i in range(n):
    if l == -1:
        l = r = I[i]
    else:
        if l < I[i] < r:
            ans *= r - l + 1 - i
            ans %= mod
        l, r = min(l, I[i]), max(r, I[i])
print(ans)