#include <iostream>
#include <algorithm>
using namespace std;

const long long md = 1000000007;
long long cb[109][109];

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n; cin >> n;
	cb[0][0] = 1;
	for (int i = 1; i <= n; i++)
		for (int j = 0; j <= i; j++) {
			cb[i][j] = cb[i - 1][j];
			if (j) cb[i][j] = (cb[i][j] + cb[i - 1][j - 1]) % md;
		}
	int c0 = 0, c1 = 0;
	for (int i = 0; i < n; i++) {
		int a; cin >> a;
		if (a > 50) c0++;
		else if (a < 50) c1++;
	}
	long long ans = 0;
	for (int i = 1; i <= c0; i += 2)
		for (int j = 0; j <= c1; j++)
			ans = (ans + cb[c0][i] * cb[c1][j]) % md;
	cout << ans << '\n';
	return 0;
}