from collections import defaultdict

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

d = defaultdict(int)
res = 0
for i in range(N):
    res += d[A[i]-1]
    res %= mod
    d[A[i]] += 1+d[A[i]-1]
    d[A[i]] %= mod
print(res)