#include <bits/stdc++.h>
using namespace std;
 
#define fi first
#define se second
#define pb push_back
using vi = vector <int>;
using ll = long long;
using pii = pair <int, int>;
//~ const ll mod = 998244353;
const ll mod = 1e9 + 7;
ll qpow(ll a, ll b, ll m = mod) { ll r = 1, t = a;
	for(; b; b /= 2) { if(b & 1) r = r * t % m; t = t * t % m; } return r; }

const int N = 111;

ll inv[N], fac[N], ifac[N];
ll binom(int n, int m) {
	if(n < m || m < 0) return 0; // n >= 0
	return fac[n] * ifac[m] % mod * ifac[n - m] % mod;
}

int main() {
	inv[1] = fac[0] = ifac[0] = 1;
	for(int i = 2; i < N; i ++)
		inv[i] = (mod - mod / i) * inv[mod % i] % mod;
	for(int i = 1; i < N; i ++) {
		fac[i] = i * fac[i - 1] % mod;
		ifac[i] = inv[i] * ifac[i - 1] % mod;
	}
	ios :: sync_with_stdio(false);
	
	int n; cin >> n;
	int c0 = 0, c1 = 0;
	for(int i = 1; i <= n; i ++) {
		int x; cin >> x;
		if(x < 50) c0 ++;
		if(x > 50) c1 ++;
	}
	
	ll ans = 0;
	for(int i = 0; i <= c0; i ++)
		for(int j = 1; j <= c1; j += 2) {
			ans += binom(c0, i) * binom(c1, j) % mod;
			ans %= mod;
		}
	cout << ans << '\n';
}