#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
#include<iomanip>
#include<queue>
using namespace std;

const int mod=998244353;
const int r=100000;
int k=0;
int a[r+10]={};
long long f[r+10]={};

void first(){
	f[1]=1;
	f[2]=2;
	for(int i=3;i<=k;i++)
		f[i]=i*f[i-1]%mod;
}
void work(){
	bool flag=true;
	long long sum=0;
	for(int i=1;i<=k;i++)
	{
		if(a[i]!=1)
		{
			flag=false;
			sum+=a[i]-1;
		}
	}
	if(flag)	cout<<1<<endl;
	else	cout<<f[k]/(sum%mod)%mod<<endl;
}
int main(){
	freopen("asm_formation.in","r",stdin);
	freopen("asm_formation.out","w",stdout);
	
	cin>>k;
	for(int i=1;i<=k;i++)	scanf("%d",&a[i]);
	first();
	work();
	
	fclose(stdin);fclose(stdout);
	return 0;
}