from collections import defaultdict

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

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

print(ans)