#include <bits/stdc++.h>
using namespace std;
constexpr int MAXN = 14;
int arr[MAXN];
int masks[1 << MAXN];
int add_mod(int a, int b) { return (a + b) % 1000000007; }
int mult_mod(int a, int b) { return (int)((((long long)a) * b) % 1000000007); }
int neg_mod(int a) { return (1000000007 - a) % 1000000007; }
long long powmod(int base, int e) {
  if (e == 0) return 1;
  long long tmp = powmod(base, e / 2);
  tmp *= tmp;
  tmp %= 1000000007;
  if (e & 1) {
    tmp *= base;
    tmp %= 1000000007;
  }
  return tmp;
}
int inv(int a) { return (int)powmod(a, 1000000007 - 2); }
int divi(int a, int b) { return mult_mod(a, inv(b)); }
int prob[MAXN][MAXN];
int noneness_cache[MAXN][1 << MAXN];
int32_t main() {
  ios_base::sync_with_stdio(false);
  int n;
  cin >> n;
  for (int i = 0; i < n; ++i) {
    cin >> arr[i];
  }
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < n; ++j) {
      prob[i][j] = divi(arr[i], add_mod(arr[i], arr[j]));
    }
  }
  for (int i = 0; i < n; ++i) {
    for (unsigned bm = 0; bm < (1u << n); ++bm) {
      int noneness = 1;
      for (int k = 0; k < n; ++k) {
        if ((1u << k) & bm) {
          noneness = mult_mod(noneness, prob[i][k]);
        }
      }
      noneness_cache[i][bm] = add_mod(1, neg_mod(noneness));
    }
  }
  int ans = 0;
  for (int i = 0; i < n; ++i) {
    for (unsigned bm = 0; bm != (1u << n); ++bm) {
      if ((bm & (1u << i)) == 0) {
        masks[bm] = 0;
      } else if (bm == (1u << i)) {
        masks[bm] = 1;
      } else {
        int total = 0;
        auto bm_popcnt = __builtin_popcount(bm);
        for (unsigned b2 = (bm - 1) & bm; b2 != 0; b2 = (b2 - 1) & bm) {
          int eff = masks[b2];
          unsigned diff = bm ^ b2;
          for (int j = 0; j < n; ++j) {
            if ((1 << j) & diff) {
              eff = mult_mod(eff, noneness_cache[j][b2]);
            }
          }
          auto b2_popcnt = __builtin_popcount(b2);
          if ((bm_popcnt - b2_popcnt) & 1) {
            total = add_mod(total, eff);
          } else {
            total = add_mod(total, neg_mod(eff));
          }
        }
        masks[bm] = total;
      }
    }
    ans = add_mod(ans, masks[(1u << n) - 1u]);
    for (unsigned bm = 0; bm != (1u << n); ++bm) {
      masks[bm] = 0;
    }
  }
  cout << ans << '\n';
}
