#define _CRT_SECURE_NO_WARNINGS #define _SILENCE_ALL_CXX17_DEPRECATION_WARNINGS #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; #define LONG_INF 10000000000000 #define GOLD 1.61803398874989484820458 #define MAX_MOD 1000000007 #define MOD 998244353LL #define seg_size 65536*4 #define REP(i,n) for(long long i = 0;i < n;++i) class Point{ public: long double x; long double y; const Point operator*(const long double &a) { Point ans; ans.x = x * a; ans.y = y * a; return ans; } const Point operator=(const Point &a){ x = a.x; y = a.y; return *this; } const Point operator+(const Point &a) const{ Point ans; ans.x = a.x + x; ans.y = a.y + y; return ans; } const Point operator+=(const Point &a){ x += a.x; y += a.y; return *this; } const Point operator-(const Point &a) const{ Point ans; ans.x = x - a.x; ans.y = y - a.y; return ans; } const Point operator-=(const Point &a) { x -= a.x; y -= a.y; return *this; } static long double inner(const Point &a, const Point &b) { return a.x * b.x + a.y * b.y; } static long double cross(const Point &a, const Point &b) { return a.x * b.y - a.y * b.x; } static Point norms(const Point &a) { long double hoge = abs(a); Point ans; ans.x = a.x / hoge; ans.y = a.y / hoge; return ans; } static long double abs(const Point &a) { return sqrtl(a.x * a.x + a.y * a.y); } }; long long gyaku(long long a) { long long now = MAX_MOD - 2; long long ans = 1; while (now != 0) { if (now % 2 == 1) { ans *= a; ans %= MAX_MOD; } a *= a; a %= MAX_MOD; now /= 2; } return ans; } int main() { int n; cin >> n; vector a; REP(i, n) { int b; cin >> b; a.push_back(b); } long long ans = 0; long long geko = 1; for (int i = 0; i < a.size(); ++i) { ans += geko * a[i]; ans %= MAX_MOD; geko *= gyaku(i + 1); geko %= MAX_MOD; geko *= (long long)(a.size() - i- 1LL); geko %= MAX_MOD; } cout << ans << endl; return 0; }