#include <bits/stdc++.h>

using namespace std;

#define pb push_back
#define mp(x, y) make_pair(x, y)
#define sz(c) ((int)c.size())
typedef long long ll;
typedef vector<int> vi;
typedef vector<vector<int> > vvi;

const int mod = (int)1e9 + 7;
void add (int &a, int b)
{
	a += b;
	if (a >= mod)
		a -= mod;
}
int mult (int a, int b)
{
	return (ll)a * b  % mod;
}

vi prod (const vi &left, const vi &right)
{
	vi ans(sz(left) + sz(right) - 1);
	for (int i = 0; i < sz(left); i++)
	for (int j = 0; j < sz(right); j++)
		add(ans[i + j], mult(left[i], right[j]));
	return ans;
}

void solve (int n)
{
	vi x(n);
	for (int i = 0; i < n; i++)
		cin >> x[i];

	vvi dp(n + 1, vi(n + 1));
	dp[1][1] = 1;
	for (int i = 2; i <= n; i++)
	{
		for (int j = 1; j <= i; j++)
		{
			dp[i][j] = 0;
			add(dp[i][j], mult(j, mult(i - j, dp[i - 1][j])));
			if (i - j >= 2)
				add(dp[i][j], mult(i - j, mult(i - j - 1, dp[i - 1][j])));
			if (j >= 2)
			{
				int c2 = ((ll)j * (ll)(j - 1) / 2) % mod;
				add(dp[i][j], mult(c2, dp[i - 1][j - 1]));
			}
		}
	}

	vi ans(1, 1);
	for (int i = 0; i < n; i++)
		ans = prod(ans, {1, x[i]});

	int res = 0;
	for (int i = 1; i <= n; i++)
		add(res, mult(ans[i], dp[n][i]));

	vi inv(n + 1);
	inv[1] = 1;
	for (int i = 2; i <= n; i++)
	{
		inv[i] = mult(mod / i, inv[mod % i]);
		inv[i] = mod - inv[i];
		assert(mult(inv[i], i) == 1);
	}

	for (int i = n; i >= 2; i--)
		res = mult(res, inv[i]),
		res = mult(res, inv[i - 1]);

	cout << res << endl;
}

int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0);

	int n;
	while (cin >> n)
		solve (n);

	cerr << (double)clock() / CLOCKS_PER_SEC << "\n";

	return 0;
}