from collections import defaultdict

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

dp = defaultdict(int)
ans = 0
for a in A:
    x = dp[a-1]
    if x > 0:
        ans += x
        ans %= MOD

    dp[a] += x + 1
    dp[a] %= MOD

print(ans)