#include using namespace std; #define int long long #define stoi stoll using ll=long long; using vi=vector; using pii=pair; #define ALL(c) begin(c),end(c) #define RALL(c) rbegin(c),rend(c) #define ITR(i,b,e) for(auto i=(b);i!=(e);++i) #define FORE(x,c) for(auto &&x:c) #define REPF(i,a,n) for(int i=a,i##len=(int)(n);i=0;--i) #define SZ(c) ((int)c.size()) #define CONTAIN(c,x) (c.find(x)!=end(c)) #define INSEG(l,x,r) ((l)<=(x)&&(x)<(r)) #define dump(...) #define pb push_back #define _ 0 const signed INF_=1001001001; const long long INF=1001001001001001001LL; const int DX[9]={0,1,0,-1,1,1,-1,-1,0},DY[9]={-1,0,1,0,-1,1,1,-1,0}; template ostream& operator<<(ostream &os,const vector &v) { ITR(i,begin(v),end(v))os<<*i<<(i==end(v)-1?"":" ");return os;} template istream& operator>>(istream &is,vector &v) { ITR(i,begin(v),end(v)) is>>*i;return is;} template istream& operator>>(istream &is, pair &p) { is>>p.first>>p.second;return is;} template bool chmax(T &a,const U &b){return a bool chmin(T &a,const U &b){return a>b?a=b,1:0;} template void PSUM(T& c) {partial_sum(begin(c), end(c), begin(c));} template using heap=priority_queue,greater>; struct before_main_function { before_main_function() { cin.tie(0); ios::sync_with_stdio(0); cout << setprecision(15) << fixed; // #define endl "\n" } } before_main_function; //------------------8<------------------------------------8<-------------------- template class ModInt { public: ModInt() : v(0) {} ModInt(int x) : v((x+mod)%mod) {} int value() const {return v;} const ModInt operator+(const ModInt &r) const { return ModInt(this->v + r.v); } const ModInt operator-(const ModInt &r) const { return ModInt(this->v + mod - r.v); } const ModInt operator*(const ModInt &r) const { return ModInt(this->v * r.v); } const ModInt operator/(const ModInt &r) const { return (*this * (~r)); } const ModInt operator~() const { return ModInt(bpow(this->v, mod-2)); } bool operator==(const ModInt &r) const { return this->v == r.v; } bool operator!=(const ModInt &r) const { return this->v != r.v; } ModInt& operator+=(const ModInt &r) { return *this = *this + r; } ModInt& operator-=(const ModInt &r) { return *this = *this - r; } ModInt& operator*=(const ModInt &r) { return *this = *this * r; } ModInt& operator/=(const ModInt &r) { return *this = *this * (~r); } private: int v; int bpow(int a, int b) const { int ret = 1; while (b > 0) { if (b & 1) ret = (ret * a) % mod; a = (a * a) % mod; b >>= 1; } return ret; } }; using Mint = ModInt<1000000007>; struct Factorial { static constexpr int MAX_N = 2000006; vector fact, fact_inv; Factorial(size_t size = MAX_N) : fact(size), fact_inv(size) { fact[0] = fact_inv[0] = 1; for (int i = 1; i < MAX_N; ++i) { fact[i] = fact[i - 1] * i; fact_inv[i] = ~fact[i]; } } Mint combination(int N, int R) { if (N < R) return 0; return fact[N] * fact_inv[N - R] * fact_inv[R]; } static Mint bin_pow(Mint x, int p) { if (x.value() == 0) return x; Mint prod = 1; while (p > 0) { if (p & 1) prod *= x; x *= x; p >>= 1; } return prod; } }; Factorial fact; signed main() { int N; cin >> N; Mint ans = 0; REP(i, N) { int a; cin >> a; ans += Mint(a) * fact.combination(N - 1, i); } cout << ans.value() << endl; return (0^_^0); }