#include using namespace std; struct fast_ios { fast_ios(){ cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_; #define FOR(i, begin, end) for(int i=(begin);i<(end);i++) #define REP(i, n) FOR(i,0,n) #define IFOR(i, begin, end) for(int i=(end)-1;i>=(begin);i--) #define IREP(i, n) IFOR(i,0,n) #define Sort(v) sort(v.begin(), v.end()) #define Reverse(v) reverse(v.begin(), v.end()) #define all(v) v.begin(),v.end() #define SZ(v) ((int)v.size()) #define Lower_bound(v, x) distance(v.begin(), lower_bound(v.begin(), v.end(), x)) #define Upper_bound(v, x) distance(v.begin(), upper_bound(v.begin(), v.end(), x)) #define Max(a, b) a = max(a, b) #define Min(a, b) a = min(a, b) #define bit(n) (1LL<<(n)) #define Ans(f, y, n) if(f) cout << y << endl; else cout << n << endl; #define debug(x) cout << #x << "=" << x << endl; #define vdebug(v) cout << #v << "=" << endl; REP(i, v.size()){ cout << v[i] << ","; } cout << endl; #define mdebug(m) cout << #m << "=" << endl; REP(i, m.size()){ REP(j, m[i].size()){ cout << m[i][j] << ","; } cout << endl;} #define pb push_back #define f first #define s second #define int long long #define INF 1000000000000000000 using vec = vector; using mat = vector; using Pii = pair; using PiP = pair; using PPi = pair; using bools = vector; using pairs = vector; template void readv(vector &a){ REP(i, a.size()) cin >> a[i]; } void readv_m1(vector &a){ REP(i, a.size()){cin >> a[i]; a[i]--;} } //int dx[4] = {1,0,-1,0}; //int dy[4] = {0,1,0,-1}; int mod = 1000000007; //int mod = 998244353; #define Add(x, y) x = (x + (y)) % mod #define Mult(x, y) x = (x * (y)) % mod int modpow(int x, int n, int m){ int a = 1; IREP(i, 64){ a = (a * a) % m; if(((n >> i) & 1) == 1) a = (a * x) % m; } return a; } class Combination { public: vec fact, invfact; int MAX_N, mod; Combination(int MAX_N, int mod): MAX_N(MAX_N), mod(mod) { initialize(); } void initialize(){ fact = vec(MAX_N + 1); invfact = vec(MAX_N + 1); fact[0] = 1; FOR(i, 1, MAX_N + 1){ fact[i] = (fact[i - 1] * i) % mod; } invfact[MAX_N] = modpow(fact[MAX_N], mod - 2, mod); IREP(i, MAX_N){ invfact[i] = (invfact[i + 1] * (i + 1)) % mod; } } int nCr(int n, int r){ if(r > n || r < 0 || n < 0) return 0; if(n > MAX_N){ MAX_N = n; initialize(); } int a = fact[n]; a = (a * invfact[r]) % mod; a = (a * invfact[n - r]) % mod; return a; } int nPr(int n, int r){ if(r > n || r < 0 || n < 0) return 0; if(n > MAX_N){ MAX_N = n; initialize(); } int a = fact[n]; a = (a * invfact[n - r]) % mod; return a; } }; signed main(){ int N; cin >> N; vec a(N); readv(a); Combination C(N, mod); int ans = 0; REP(i, N) Add(ans, a[i] * C.nCr(N - 1, i)); cout << ans << endl; return 0; }