func_code_string: #include <bits/stdc++.h>   using namespace std;   int recur_depth = 0;   const long long sz = 14, isz = 2e6 + 10, mod = 1e9 + 7;   long long p[sz], win[sz][sz], scc[(1 << sz)], n;   long long fastPow(long long x, long long n, long long MOD) {     long long ret = 1;     while (n) {       if (n & 1) ret = (ret * x) % MOD;       x = (x * x) % MOD;       n >>= 1;     }     return ret % MOD;   }   inline long long inv(long long x) { return fastPow(x, mod - 2, mod); }   long long prob(long long from, long long to) {     long long ret = 1;     for (long long i = 0; i < n; ++i) {       for (long long j = 0; j < n; ++j) {         if ((from >> i & 1) && (to >> j & 1)) ret = (ret * win[i][j]) % mod;       }     }     return ret;   }   int main() {     std::ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     ;     cin >> n;     for (long long i = 0; i < n; ++i) cin >> p[i];     for (long long i = 0; i < n; ++i)       for (long long j = 0; j < n; ++j)         win[i][j] = (p[i] * inv(p[i] + p[j])) % mod;     long long ans = 0, lim = (1 << n) - 1;     for (int mask = 0; mask <= lim; mask++) {       scc[mask] = 1;       for (int i = mask; i > 0; i = (i - 1) & mask) {         if (i == mask) continue;         scc[mask] -= (scc[i] * prob(i, mask ^ i)) % mod;         if (scc[mask] < 0) scc[mask] += mod;       }       long long win_prob = (scc[mask] * __builtin_popcount(mask)) % mod;       win_prob = (win_prob * prob(mask, lim ^ mask)) % mod;       ans += win_prob;       if (ans >= mod) ans -= mod;     }     cout << ans <<   n ;     return 0;   }   