#include using namespace std; #define int long long #define pb push_back #define fi first #define se second #define FOR(i,n) for(int i = 0;i=(s);i--) #define all(v) (v).begin(),(v).end() #define chmin(a,b) a=min((a),(b)) #define chmax(a,b) a=max((a),(b)) #define endl '\n' #define IOS() ios_base::sync_with_stdio(0);cin.tie(0) typedef long long ll; typedef pairpint; typedef vectorvint; typedef vectorvpint; const ll MOD=1000000007,INF=1ll<<60; int dx[]={0,0,1,-1}; int dy[]={-1,1,0,0}; typedef pairP2; typedef vectorvvint; int N; const int MAX = 510000; long long fac[MAX], finv[MAX], inv[MAX]; // テーブルを作る前処理 void COMinit() { fac[0] = fac[1] = 1; finv[0] = finv[1] = 1; inv[1] = 1; for (int i = 2; i < MAX; 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; } } // 二項係数計算 long long COM(int n, int k){ if (n < k) return 0; if (n < 0 || k < 0) return 0; return fac[n] * (finv[k] * finv[n - k] % MOD) % MOD; } signed main() { IOS(); COMinit(); cin>>N; vint v(N); rep(i,0,N)cin>>v[i]; int ans=0; rep(i,0,N){ (ans+=v[i]*COM(N-1,i))%=MOD; } cout<