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

ptoi = [0]*n
for i, p in enumerate(P):
    ptoi[p] = i

ans = 1
l = ptoi[0]
r = ptoi[0]
for p in range(1, n):
    i = ptoi[p]
    nl, nr = min(l, i), max(r, i)
    if (l, r) == (nl, nr):
        ans *= (r-l+1-p)
        ans %= mod
    l, r = nl, nr
print(ans)