#include<bits/stdc++.h>
using namespace std;
constexpr int M=1005,mod=998244353;
int n,m,ans,c[M][M],dp[M][M];
int read(){
	int x=0;char ch=getchar();
	while (!isdigit(ch)) ch=getchar();
	while (isdigit(ch)) x=x*10+ch-48,ch=getchar();
	return x;
}
int rdc(int x){return x>=mod?x-mod:x;}
int calc(int n,int m){return c[n+m-1][m-1];}
int main(){ n=read();
	for (int i=0;i<=1000;i++)
		for (int j=c[i][0]=1;j<=i;j++)
			c[i][j]=rdc(c[i-1][j]+c[i-1][j-1]);
	dp[0][0]=1;
	for (int i=1;i<=n;i++){
		int x=read();
		for (int j=0;j<=m;j++) dp[i][j+x]=dp[i-1][j];
		for (int j=1;j<=m;j++)
			for (int k=j;k<=m;k++) if (dp[i-1][k])
				for (int p=0;p<x;p++)
					dp[i][j+p]=(dp[i][j+p]+1ll*dp[i-1][k]*calc(x-p-1,k-j+1))%mod;
		m+=x;
	}
	for (int i=0;i<=m;i++) ans=rdc(ans+dp[n][i]);
	printf("%d\n",ans);
	return 0;
}