#include <bits/stdc++.h>
using namespace std;
const int P = 1e9 + 7, N = 17, M = 16389, O = 131;
int qp(int a, int b) {
  int r = 1;
  for (; b; b >>= 1, a = a * 1ll * a % P)
    if (b & 1) r = r * 1ll * a % P;
  return r;
}
int a[N], e[N][N], p[M], n, ll[O][O], lr[O][O], rl[O][O], rr[O][O];
int g(int x, int y) {
  int i, j, s = 1;
  for (i = 0; i < n; ++i)
    if (x >> i & 1)
      for (j = 0; j < n; ++j)
        if (y >> j & 1) s = s * 1ll * e[i][j] % P;
  return s;
}
int h(int x, int y) {
  return ll[x & 127][y & 127] * 1ll * lr[x & 127][y >> 7] % P *
         rl[x >> 7][y & 127] % P * rr[x >> 7][y >> 7] % P;
}
int main() {
  int m, i, j, w = 0;
  scanf("%d", &n);
  for (i = 0; i < n; ++i) scanf("%d", a + i);
  for (i = 0; i < n; ++i)
    for (j = 0; j < n; ++j) e[i][j] = a[i] * 1ll * qp(a[i] + a[j], P - 2) % P;
  for (i = 0; i < O; ++i)
    for (j = 0; j < O; ++j) ll[i][j] = lr[i][j] = rl[i][j] = rr[i][j] = 1;
  for (i = 0, m = 1 << min(n, 7); i < m; ++i)
    for (j = 0; j < m; ++j)
      if (!(i & j)) ll[i][j] = g(i, j);
  if (n > 7) {
    for (i = 0, m = 1 << n - 7; i < 128; ++i)
      for (j = 0; j < m; ++j) lr[i][j] = g(i, j << 7);
    for (i = 0; i < m; ++i)
      for (j = 0; j < 128; ++j) rl[i][j] = g(i << 7, j);
    for (i = 0; i < m; ++i)
      for (j = 0; j < m; ++j)
        if (!(i & j)) rr[i][j] = g(i << 7, j << 7);
  }
  for (i = 1, m = 1 << n; i < m;
       w = (w + p[i] * 1ll * h(i, m - 1 ^ i) % P * __builtin_popcount(i)) % P,
      ++i)
    for (p[i] = 1, j = i & i - 1; j; j = j - 1 & i)
      p[i] = (p[i] - p[j] * 1ll * h(j, i ^ j)) % P;
  printf("%d", (w + P) % P);
  return 0;
}
