import sys
input = sys.stdin.readline
from collections import *

N = int(input())
A = list(map(int, input().split()))
d = defaultdict(int)
MOD = 998244353

for Ai in A:
    d[Ai] += 1+d[Ai-1]
    d[Ai] %= MOD

ans = (sum(d.values())-N)%MOD
print(ans)