N=int(input())
A=list(map(int,input().split()))
dp=[[0]*(10**5+1) for i in range(N+1)]
v=[[0]*(10**5+1) for i in range(N+1)]
for i in range(A[0],10**5+1):
  dp[1][i]=1
for i in range(10**5+1):
  v[1][i]=v[1][i-1]+dp[1][i]
mod=998244353
for i in range(1,N):
  if A[i]>=A[i-1]:
    for j in range(A[i],10**5+1):
      w=j-(A[i]-A[i-1])
      if w<0:
        continue
      dp[i+1][j]=v[i][w]
  else:
    for j in range(A[i],10**5+1):
      dp[i+1][j]=v[i][j]
  for j in range(10**5+1):
    v[i+1][j]=v[i+1][j-1]+dp[i+1][j]
    v[i+1][j]%=mod
print(v[N][10**5])