func_code_string: #include <bits/stdc++.h>   using namespace std;   using uint = unsigned int;   using ll = long long;   const int M = 1e9 + 7;   const ll MLL = 1e18L + 9;   #pragma unused(M)   #pragma unused(MLL)   template <ostream& out = cout, class... T>   void prints(T&&...) {}   template <ostream& out = cout, class... T>   void printd(T&&...) {}   template <ostream& out = cout, class... T>   void printb(T&&...) {}   template <ostream& out = cout, class... T>   void printArr(T&&...) {}   ll modPow(ll base, ll ex, ll m) {     ll ret = 1;     while (ex) {       if (ex & 1) {         ret = ret * base % m;       }       ex >>= 1;       base = base * base % m;     }     return ret;   }   ll modFact(ll n, ll m) {     if (!n) {       return 1;     }     static vector<ll> memo = {1, 1};     if (n < (ll)memo.size()) {       return memo[n];     }     for (int i = memo.size(); i <= n; i++) {       memo.push_back(memo.back() * i % m);     }     return memo[n];   }   pair<ll, pair<ll, ll>> exGCD(ll a, ll b) {     bool inv = false;     if (a < b) {       swap(a, b);       inv = true;     }     vector<ll> r = {a, b}, ks;     while (b) {       ks.push_back(a / b);       r.push_back(a = a % b);       swap(a, b);     }     ll gcd = a;     ll x = 0, y = 1, u = 1, v = -ks[0];     for (unsigned long i = 1; i < ks.size(); i++) {       ll k = ks[i];       ll x2 = u, y2 = v, u2 = x - k * u, v2 = y - k * v;       x = x2;       y = y2;       u = u2;       v = v2;     }     if (inv) {       swap(x, y);     }     return {gcd, {x, y}};   }   ll modInv(ll n, ll m) {     return modPow(n, m - 2, m);     auto p = exGCD(n, m);     return (p.second.first + m) % m;   }   ll modC(ll n, ll k, ll m) {     return modFact(n, m) * modInv(modFact(k, m) * modFact(n - k, m) % m, m) % m;   }   int solve(vector<int> as) {     bool p = true;     int n = as.size();     for (int i = 0; i < n - 1; i++) {       for (int j = 0; j < n - i - 1; j++) {         as[j] = as[j] + as[j + 1] * (p ? 1 : -1);         p = !p;       }     }     return as[0];   }   int main() {     cin.tie(0);     ios::sync_with_stdio(false);     int n;     cin >> n;     vector<int> as(n);     for (int i = 0; i < n; i++) {       cin >> as[i];     }     for (int i = 1; i <= 31; i++) {       vector<int> as(i, 1), diffs(i);       int n1 = solve(as);       for (int j = 0; j < i; j++) {         as[j]++;         diffs[j] = solve(as) - n1;         as[j]--;       }       prints(i / 4, diffs);     }     int num = n / 4;     vector<int> v1, v2, v3, v4;     for (int i = 0; i < num; i++) {       int mc = modC(2 * num - 1, i, M);       v1.push_back(mc);       v1.push_back(-mc);     }     for (int i = 0; i < num; i++) {       int mc2 = modC(2 * num, i, M);       v2.push_back(mc2);       v2.push_back(0);       v3.push_back(mc2);       v3.push_back(mc2);     }     int mc2 = modC(2 * num, num, M);     v2.push_back(mc2);     v3.push_back(mc2);     {       vector<int> vv(v1.rbegin(), v1.rend());       v1.insert(v1.end(), vv.begin(), vv.end());     }     for (int i = v1.size() / 2; i < v1.size(); i++) {       v1[i] *= -1;     }     {       vector<int> vv(v2.rbegin() + 1, v2.rend());       v2.insert(v2.end(), vv.begin(), vv.end());     }     {       vector<int> vv(v3.rbegin(), v3.rend());       v3.insert(v3.end(), vv.begin(), vv.end());     }     v4 = v3;     for (uint i = 0; i < v4.size(); i++) {       if (i & 1) {         v4[i] *= 2;       } else if (i) {         v4[i] -= v3[i - 2];       }     }     v4.push_back(-v4[0]);     prints(1);     prints(num, v1);     prints(num, v2);     prints(num, v3);     prints(num, v4);     int r = n % 4;     auto& vvv = (r == 0 ? v1 : r == 1 ? v2 : r == 2 ? v3 : v4);     ll ans = 0;     for (int i = 0; i < n; i++) {       ans = (ans + 1ll * vvv[i] * as[i] + M) % M;     }     cout << ans <<   n ;     return 0;   }   