#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll,ll> P;
#define pb emplace_back
#define fi first
#define se second
#define mkp make_pair
const ll mod = 998244353;
inline ll read() { ll x; scanf("%lld",&x); return x; }
inline ll lg2(ll x){ return 63^__builtin_clzll(x); }
inline ll qpow(ll a,ll b){
	ll ans=1, base=a;
	while(b){
		if(b&1) ans=ans*base%mod;
		base=base*base%mod; b>>=1;
	}
	return ans;
}

ll n,a[505],f[505][505];
void init(){ }

inline void addmod(ll &a, ll b){
	a += b; if(a >= mod) a -= mod;
}
inline void Addmod(ll &a, ll b){
	a = (a + b) % mod;
}
ll C[505][505];
void procedure(){
	n=read();	
	C[0][0]=1;
	for(ll i=1;i<=n;i++){
		C[i][0]=1;
		for(ll j=1;j<=i;j++){
			C[i][j]=(C[i-1][j]+C[i-1][j-1])%mod;
		}
	}
	for(ll i=1;i<=n;i++) a[i]=read();
	f[0][0]=1;
	for(ll i=0;i<n;i++){
		for(ll j=0;j<=n;j++){
			if(!f[i][j]) continue;
			// cout<<"here "<<i<<", "<<j<<" has "<<f[i][j]<<endl;
			addmod(f[i+1][j+a[i+1]], f[i][j]);
			// cout<<"trans to "<<i+1<<" "<<j+a[i]<<endl;
			for(ll k=0;k<j;k++){
				for(ll l=0;l<a[i+1];l++){
					if(l) Addmod(f[i+1][j-k+l], f[i][j] * C[l-1+j-k][j-k]);
					else addmod(f[i+1][j-k+l], f[i][j]);
				}
			}
		}
	}
	ll ans=0;
	for(ll i=0;i<=n;i++) addmod(ans, f[n][i]);
	printf("%lld\n", ans);
}
int main(){
	#ifdef LOCAL
		assert(freopen("input.txt","r",stdin));
		assert(freopen("output.txt","w",stdout));
	#endif
	ll T=1; init();
	// T=read();
	while(T--) procedure();
	return 0;
}