#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
const int mod=998244353;
const int N=2005;
int n,a[N],dp[N][N],C[N][N];// dp[i][j] i-1 个数还剩下 j 个 
bool cmp(int a,int b){
	return a>b;
}
int main(){
	freopen("gamem.in","r",stdin);
	freopen("gamem.out","w",stdout); 
	scanf("%d",&n);
	for(int i=1;i<=n;i++)scanf("%d",a+i);
	sort(a+1,a+1+n,cmp);
	C[0][0]=1;
	for(int i=1;i<=n;i++){
		C[i][0]=C[i][i]=1;
		for(int j=1;j<i;j++){
			C[i][j]=(C[i-1][j]+C[i-1][j-1])%mod;
		} 
	}
	dp[1][0]=1;
	for(int i=1;i<=n;i++){
		for(int j=0;j<i;j++){
			dp[i+1][j+1]+=dp[i][j];
			dp[i+1][j+1]%=mod;
			for(int k=0;k<=min(a[i]-1,j);k++){
				dp[i+1][j-k]+=1ll*dp[i][j]*C[j][k]%mod;
				dp[i+1][j-k]%=mod;
			}
		}
	}
	cout<<dp[n+1][0]<<endl;
	return 0;
}