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

from collections import defaultdict
ans = 0
P = 998244353

d = defaultdict(int)

for a in A:
    ans += d[a-1]
    d[a] += 1 + d[a-1]
    d[a] %= P
"""
d = defaultdict(int)
for a in A:
    ans += d[a + 1]
    d[a] += d[a + 1] + 1
    d[a] %= P
"""
print(ans % P)