def Map():
  return list(map(int,input().split()))

mod = 998244353
N = int(input())
A = Map()
S = 10**5
if N == 1:
  print(S + 1 - A[0])
  exit()
dp = [[0 for j in range(S + 2)] for i in range(N)]
for s in range(S + 1):
  if s + A[0] > S:
    break
  dp[0][s] += 1

for n in range(N-1):
  d = 0
  sss = S - A[n+1] + 1
  if A[n] - A[n+1] > 0:
    d += A[n] - A[n+1]
  for s in range(S+1):
    if n > 0 and s < S:
      dp[n][s+1] += dp[n][s]
      dp[n][s+1] %= mod
  for s in range(S+1):
    if s + d >= sss:
      break
    ss = s + d
    dp[n+1][ss] += dp[n][s]
    dp[n+1][ss] %= mod
    dp[n+1][sss] -= dp[n][s]
    dp[n+1][sss] %= mod
ans = 0
for s in range(S+1):
  dp[N-1][s+1] += dp[N-1][s]
  dp[N-1][s+1] %= mod
  ans += dp[N-1][s]
  ans %= mod
print(ans)