#include <bits/stdc++.h>
inline int fmo(int x) { return x + ((x >> 31) & 1000000007); }
inline int fp(int x, int k = 1000000007 - 2) {
  int res = 1;
  for (; k; k >>= 1, x = 1ll * x * x % 1000000007)
    if (k & 1) res = 1ll * res * x % 1000000007;
  return res;
}
int n, a[15], w[15][15];
int p[1 << 15][15];
std::unordered_map<long long, int> f;
int g[1 << 15];
int ans;
int main() {
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", &a[i]);
  for (int i = 0; i < n; i++)
    for (int j = 0; j < n; j++)
      if (i != j) w[i][j] = 1ll * a[i] * fp(a[i] + a[j]) % 1000000007;
  for (int s = 0; s < (1 << n); s++)
    for (int i = 0; i < n; i++)
      if (!((s >> i) & 1)) {
        p[s][i] = 1;
        for (int j = 0; j < n; j++)
          if ((s >> j) & 1) p[s][i] = 1ll * p[s][i] * w[i][j] % 1000000007;
      }
  for (int s = 0; s < (1 << n); s++) {
    int x = ((1 << n) - 1) ^ s;
    for (int t = x;; t = (t - 1) & x) {
      int tmp = 1;
      for (int i = 0; i < n; i++)
        if ((s >> i) & 1) tmp = 1ll * tmp * p[t][i] % 1000000007;
      f[s << n | t] = tmp;
      if (!t) break;
    }
  }
  g[0] = 0;
  for (int s = 1; s < (1 << n); s++) {
    int tmp = 1;
    for (int t = (s - 1) & s;; t = (t - 1) & s) {
      tmp = fmo(tmp - 1ll * g[t] * f[t << n | (s ^ t)] % 1000000007);
      if (!t) break;
    }
    g[s] = tmp;
    ans = fmo(ans +
              1ll * __builtin_popcount(s) * g[s] % 1000000007 *
                  f[s << n | (((1 << n) - 1) ^ s)] % 1000000007 -
              1000000007);
  }
  printf("%d\n", ans);
}
