from collections import defaultdict

n = int(input())
a = list(map(int, input().split()))

MOD = 998244353

res = 0

d = defaultdict(int)

for i in range(n):
    c = d[a[i] - 1]
    res += c
    nc = (d[a[i]] + c + 1) % MOD
    d[a[i]] = nc

print(res % MOD)