// includes #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include // macros #define ll long long int #define pb emplace_back #define mk make_pair #define pq priority_queue #define FOR(i, a, b) for(int i=(a);i<(b);++i) #define rep(i, n) FOR(i, 0, n) #define rrep(i, n) for(int i=((int)(n)-1);i>=0;i--) #define all(x) (x).begin(),(x).end() #define sz(x) ((int)(x).size()) #define UNIQUE(v) v.erase(unique(v.begin(), v.end()), v.end()) using namespace std; // types typedef pair P; typedef pair Pl; typedef pair Pll; typedef pair Pd; // constants const int inf = 1e9; const ll linf = 1LL << 50; const double EPS = 1e-10; const int mod = 1e9 + 7; // solve template bool chmax(T &a, const T &b){if(a < b){a = b; return 1;} return 0;} template bool chmin(T &a, const T &b){if(a > b){a = b; return 1;} return 0;} ll fac[100001], inv[100001]; template T power(T a, T n, T mod) { T res = 1; T tmp = n; T curr = a; while(tmp){ if(tmp % 2 == 1){ res = (T)((ll)res * curr % mod); } curr = (T)((ll)curr * curr % mod); tmp >>= 1; } return res; } int main(int argc, char const* argv[]) { ios_base::sync_with_stdio(false); cin.tie(0); int n; cin >> n; vector a(n); rep(i, n)cin >> a[i]; fac[0] = 1; for(int i = 1; i <= n; i++){ fac[i] = i * fac[i-1] % mod; } inv[n] = power(fac[n], mod - 2, mod); for(int i = n - 1; i >= 0; i--){ inv[i] = (i + 1) * inv[i+1] % mod; } ll res = 0; for(int i = 0; i < n; i++){ res = (res + (fac[n-1] * (inv[i] * inv[n-i-1] % mod) % mod * a[i]) % mod) % mod; } cout << res << endl; return 0; }