N = int(input())
P = list(map(int, input().split()))
MOD = 998244353

ind = [0] * N
for i in range(N):
    ind[P[i]] = i

ans = 1
l = r = ind[0]

for k in range(1, N):
    i = ind[k]
    nl, nr = min(l, i), max(r, i)
    if (l, r) == (nl, nr):
        ans *= r - l + 1 - k
        ans %= MOD
    l, r = nl, nr

print(ans)