N = int(input())
A = list(map(int, input().split()))
M = 10**5
pre = [0] * (M + 2)
for i in range(A[0], M + 1):
    pre[i] = 1
    
mod = 998244353
for i in range(1, N):
    dp = [0] * (M + 2)
    da = max(0, A[i] - A[i - 1])
    for j in range(M + 1):
        mi = min(M + 1 - j, da)
        dp[j + mi] += pre[j]
        dp[j + mi] %= mod
    for j in range(1, M + 1):
        dp[j] += dp[j - 1]
        dp[j] %= mod
    dp, pre = pre, dp
    
print(sum(pre[:M+1])%mod)