#include<bits/stdc++.h>
using namespace std;
#define int long long
const int nn=505,mod=998244353,mzhxi=504;
int n,a[nn],dp[nn][nn],sum,fac[nn],inv[nn],ans;
inline int poww(int x,int y){
	if(y==0) return 1;
	int g=poww(x,y/2);
	if(y&1) return g*g%mod*x%mod;
	return g*g%mod;
}
inline int C(int x,int y){
	if(x<0||y<0||x-y<0) return 0;
	return fac[x]*inv[x-y]%mod*inv[y]%mod;
}
signed main(){
	ios::sync_with_stdio(0),cin.tie(0),cout.tie(0);
	fac[0]=1;
	for(int i=1;i<=mzhxi;i++) fac[i]=fac[i-1]*i%mod;
	inv[mzhxi]=poww(fac[mzhxi],mod-2);
	for(int i=mzhxi-1;i>=0;i--) inv[i]=inv[i+1]*(i+1)%mod;
	cin>>n;
	for(int i=1;i<=n;i++) cin>>a[i];
	dp[0][0]=1;
	for(int i=0;i<n;i++,sum+=a[i]){
		for(int j=2;j<=sum;j++) dp[i+1][j+a[i]]=dp[i][j];
		dp[i+1][0]=dp[i][0];
		for(int x=0;x<a[i+1];x++){
			for(int k=1;k<=sum;k++){
				for(int j=k+1;j<=sum;j++) dp[i+1][k+1+x]=(dp[i+1][k+1+x]+dp[i][j]*C(j-k-1+a[i+1]-x-1,a[i+1]-x-1))%mod;
				dp[i+1][k+1+x]=(dp[i+1][k+1+x]+dp[i][0]*C(sum-k+a[i+1]-x-1,a[i+1]-x-1))%mod;
			}
		}
	}
	for(int j=0;j<=sum;j++) ans+=dp[n][j],ans%=mod;
	cout<<ans<<endl;
	return 0;
}