#include typedef long long ll; #define rep(i,m,n) for(ll i = (m); i < (n); i++) #define rrep(i,m,n) for(ll i = (m); i >= (n); i--) #define print(x) cout << (x) << endl; #define print2(x,y) cout << (x) << " " << (y) << endl; #define printa(x,n) for(ll i = 0; i < n; i++){ cout << (x[i]) << " \n"[i == n-1];} #define printp(x,n) for(ll i = 0; i < n; i++){ cout << "(" << x[i].first << ", " << x[i].second << ") "; } cout << endl; #define INF (1e18 + 7) using namespace std; const ll MOD = 1e9 + 7; typedef pair lpair; struct Combination{ private: ll N; vector fac, facinv; public: Combination(ll n){ N = n; fac.push_back(1); fac.push_back(1); rep(i,2,N+1) fac.push_back(fac[i-1] * i % MOD); rep(i,0,N+1) facinv.push_back(power(fac[i], MOD-2)); } ll power(ll x, ll n){ if(n == 0) return 1LL; ll res = power(x * x % MOD, n/2); if(n % 2 == 1) res = res * x % MOD; return res; } ll nck(ll n, ll k){ if(k == 0 || n == k) return 1LL; return fac[n] * facinv[k] % MOD * facinv[n-k] % MOD; } ll npk(ll n, ll k){ if(k == 0 || n == k) return 1LL; return fac[n] * facinv[n-k] % MOD; } ll get(ll x){return fac[x];}; ll getinv(ll x){return facinv[x];}; }; int main(){ cin.tie(0); ios::sync_with_stdio(false); ll N; ll A[100010]; cin >> N; rep(i,0,N) cin >> A[i]; Combination comb(100010); ll ans = 0; rep(i,0,N){ ans += comb.nck(N-1, i) * A[i] % MOD; ans %= MOD; } print(ans); }