import sys
sys.setrecursionlimit(5*10**5)
input = sys.stdin.readline
from collections import defaultdict, deque, Counter
from heapq import heappop, heappush
from bisect import bisect_left, bisect_right
from math import gcd
class Binom:
    def __init__(self, n, mod):
        self.n = n
        self.mod = mod
        self.fact = [1,1]
        self.factinv = [1,1]
        self.inv = [0,1]
        self._calc(n, mod)
    
    def _calc(self, n, mod):
        for i in range(2, n+1):
            self.fact.append((self.fact[-1]*i) % mod)
            self.inv.append((-self.inv[mod % i]*(mod//i)) % mod)
            self.factinv.append((self.factinv[-1]*self.inv[-1]) % mod)

    def comb(self,n,r):
        return self.fact[n]*self.factinv[r]%self.mod*self.factinv[n-r]%self.mod
    
    def perm(self,n,r):
        return self.fact[n]*self.factinv[n-r]%self.mod



mod = 998244353
binom = Binom(10**5+10, mod)
n = int(input())
a = list(map(int,input().split()))
d = [0]
for i in range(1, n):
    d.append(max(0, -(a[i] - a[i-1])))
left = []
now = 0
for i in range(n):
    now += d[i]
    tmp = a[i] + now
    left.append(10**5-tmp)
last = left[-1]
ans = 0
if last < 0:
    print(0)
    exit()
for i in range(last+1):
    ans += binom.comb(n+i-1, i)
    ans %= mod
    # print(i, ans)

print(ans)