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

P = 998244353
C = 10 ** 5 + 1
dp = [0] * C
for i in range(A[0],C):
    dp[i] = 1
for i in range(1,N):
    a = A[i]
    bef = A[i-1]
    nx = [0] * C
    S = [0] * C
    S[0] = dp[0]
    for j in range(1,C):
        S[j] = S[j-1] + dp[j]
        S[j] %= P
    for j in range(a,C):
        b = j - a
        v = min(bef + b,j)
        if v < bef:continue
        else:
            t = S[v]
            nx[j] = t
    dp = nx
S = sum(dp)
print(S % P)