from collections import *

def calc(A):
    D = defaultdict(int)
    mod = 998244353
    val = 0
    for i in range(N):
        v = D[A[i] - 1]
        D[A[i]] += v + 1
        D[A[i]] %= mod
        val += v
        val %= mod
    return val

N = int(input())
A = list(map(int, input().split()))
print(calc(A))