from collections import defaultdict

MOD = 998244353

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

dp = defaultdict(int)
cnt = defaultdict(int)
ans = 0

for v in a:
    prev = v - 1
    delta = (dp[prev] + cnt[prev]) % MOD
    ans = (ans + delta) % MOD
    dp[v] = (dp[v] + delta) % MOD
    cnt[v] += 1

print(ans % MOD)