#include <bits/stdc++.h>

using namespace std;

const int N = 510, mod = 998244353;
typedef long long LL;

int n, m, w[N];
int fc[N], ifc[N];
int f[N][N], g[N][N];

int inv(int x) {
	int y = mod - 2, z = 1;
	while (y) {
		if (y & 1) z = (LL)z * x % mod;
		x = (LL)x * x % mod; y >>= 1;
	} return z; 
}
int binom(int x, int y) {
	if (x < 0 || y < 0 || x < y) return 0;
	return (LL)fc[x] * ifc[y] % mod * ifc[x - y] % mod;
}
inline void addt(int &x, int y) { x += y, x >= mod && (x -= mod); }

int main() {
	scanf("%d", &n);
	for (int i = 1; i <= n; i ++ ) scanf("%d", &w[i]), m += w[i];
	
	fc[0] = ifc[0] = 1;
	for (int i = 1; i <= m; i ++ ) {
		fc[i] = (LL)fc[i - 1] * i % mod;
		ifc[i] = inv(fc[i]);
	}
	
	f[1][0] = 1;
	for (int i = 1, s = w[1]; i < n; i ++ , s += w[i]) {
		// 0 
		addt(f[i + 1][0], f[i][0]);
		for (int k = 1; k <= s; k ++ ) {
			for (int x = 0; x < w[i + 1]; x ++ ) {
				int val = binom(s - k + w[i + 1] - x - 1, w[i + 1] - x - 1);
				addt(f[i + 1][x + k + 1], (LL)f[i][0] * val % mod);
			} // k + 1 ~ s
		}
		for (int j = 1; j <= m; j ++ ) {
			addt(f[i + 1][j + w[i + 1]], f[i][j]);
			for (int k = 1; k < j; k ++ ) {
				for (int x = 0; x < w[i + 1]; x ++ ) {
					int val = binom(j - k - 1 + w[i + 1] - x - 1, w[i + 1] - x - 1);
					addt(f[i + 1][x + k + 1], (LL)f[i][j] * val % mod);
				}
			}
		}
	} 
//	for (int i = 1; i <= n; i ++ , puts("")) for (int j = 0; j <= m; j ++ ) cout << f[i][j] << ' ';
	int res = 0;
	for (int i = 0; i <= m; i ++ ) addt(res, f[n][i]);
	printf("%d\n", res); return 0;
}