#include using namespace std; using ll = long long; using ull = unsigned long long; #define ALL(obj) (obj).begin(),(obj).end() #define SPEED cin.tie(0);ios::sync_with_stdio(false); template using PQ = priority_queue; template using PQR = priority_queue,greater>; constexpr long long MOD = (long long)1e9 + 7; constexpr long long MOD2 = 998244353; constexpr long long HIGHINF = (long long)1e18; constexpr long long LOWINF = (long long)1e15; constexpr long double PI = 3.1415926535897932384626433; template vector multivector(size_t N,T init){return vector(N,init);} template auto multivector(size_t N,T... t){return vector(N,multivector(t...));} template void corner(bool flg, T hoge) {if (flg) {cout << hoge << endl; exit(0);}} template ostream &operator<<(ostream &o, const map&obj) {o << "{"; for (auto &x : obj) o << " {" << x.first << " : " << x.second << "}" << ","; o << " }"; return o;} template ostream &operator<<(ostream &o, const set&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;} template ostream &operator<<(ostream &o, const multiset&obj) {o << "{"; for (auto itr = obj.begin(); itr != obj.end(); ++itr) o << (itr != obj.begin() ? ", " : "") << *itr; o << "}"; return o;} template ostream &operator<<(ostream &o, const vector&obj) {o << "{"; for (int i = 0; i < (int)obj.size(); ++i)o << (i > 0 ? ", " : "") << obj[i]; o << "}"; return o;} template ostream &operator<<(ostream &o, const pair&obj) {o << "{" << obj.first << ", " << obj.second << "}"; return o;} void print(void) {cout << endl;} template void print(Head&& head) {cout << head;print();} template void print(Head&& head, Tail&&... tail) {cout << head << " ";print(forward(tail)...);} template void chmax(T& a, const T b){a=max(a,b);} template void chmin(T& a, const T b){a=min(a,b);} void YN(bool flg) {cout << (flg ? "YES" : "NO") << endl;} void Yn(bool flg) {cout << (flg ? "Yes" : "No") << endl;} void yn(bool flg) {cout << (flg ? "yes" : "no") << endl;} template class ModInt { public: long long x; ModInt():x(0) { // do nothing } ModInt(long long y) : x(y>=0?(y%mod): (mod - (-y)%mod)%mod) { // do nothing } ModInt &operator+=(const ModInt &p) { if((x += p.x) >= mod) x -= mod; return *this; } ModInt &operator+=(const long long y) { ModInt p(y); if((x += p.x) >= mod) x -= mod; return *this; } ModInt &operator+=(const int y) { ModInt p(y); if((x += p.x) >= mod) x -= mod; return *this; } ModInt &operator-=(const ModInt &p) { if((x += mod - p.x) >= mod) x -= mod; return *this; } ModInt &operator-=(const long long y) { ModInt p(y); if((x += mod - p.x) >= mod) x -= mod; return *this; } ModInt &operator-=(const int y) { ModInt p(y); if((x += mod - p.x) >= mod) x -= mod; return *this; } ModInt &operator*=(const ModInt &p) { x = (x * p.x % mod); return *this; } ModInt &operator*=(const long long y) { ModInt p(y); x = (x * p.x % mod); return *this; } ModInt &operator*=(const int y) { ModInt p(y); x = (x * p.x % mod); return *this; } ModInt &operator/=(const ModInt &p) { *this *= p.inv(); return *this; } ModInt &operator/=(const long long y) { ModInt p(y); *this *= p.inv(); return *this; } ModInt &operator/=(const int y) { ModInt p(y); *this *= p.inv(); return *this; } ModInt operator=(const int y) { ModInt p(y); *this = p; return *this; } ModInt operator=(const long long y) { ModInt p(y); *this = p; return *this; } ModInt operator-() const { return ModInt(-x); } ModInt operator++() { x++; if(x>=mod) x-=mod; return *this; } ModInt operator--() { x--; if(x<0) x+=mod; return *this; } ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; } ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; } ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; } ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; } bool operator==(const ModInt &p) const { return x == p.x; } bool operator!=(const ModInt &p) const { return x != p.x; } ModInt inv() const { int a = x, b = mod, u = 1, v = 0, t; while(b > 0) { t = a / b; swap(a -= t * b, b); swap(u -= t * v, v); } return ModInt(u); } ModInt pow(long long n) const { ModInt ret(1), mul(x); while(n > 0) { if(n & 1) ret *= mul; mul *= mul; n >>= 1; } return ret; } friend ostream &operator<<(ostream &os, const ModInt &p) { return os << p.x; } friend istream &operator>>(istream &is, ModInt &a) { long long t; is >> t; a = ModInt(t); return (is); } }; using modint = ModInt; //Combination Mod class CombinationMod { public: vector fac,finv,inv; long long mod; CombinationMod(int N,long long mod) : fac(N + 1), finv(N + 1), inv(N + 1), mod(mod) { fac[0] = fac[1] = finv[0] = finv[1] = inv[1] = 1; for (int i = 2; i <= N; ++i) { fac[i] = fac[i - 1] * i % mod; inv[i] = mod - inv[mod%i] * (mod / i) % mod; finv[i] = finv[i - 1] * inv[i] % mod; } } long long num(int n, int k) { return ((n < 0 || k < 0 || n < k) ? 0 : fac[n] * (finv[k] * finv[n - k] % mod) % mod); } }; //verify https://atcoder.jp/contests/abc021/tasks/abc021_d int main() { int N; cin >> N; CombinationMod CM(N,MOD); modint ans = 0; for(int i = 0; i < N; ++i){ modint A; cin >> A; ans += A*CM.num(N-1,i); } cout << ans << endl; return 0; }