func_code_string: #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;   }   