p = 10**9+7 N = int(input()) A = list(map(int, input().split())) def cmb(n, r, p): if (r < 0) or (n < r): return 0 r = min(r, n - r) return fact[n] * factinv[r] * factinv[n-r] % p fact = [1, 1] # fact[n] = (n! mod p) factinv = [1, 1] # factinv[n] = ((n!)^(-1) mod p) inv = [0, 1] # factinv 計算用 for i in range(2, N + 1): fact.append((fact[-1] * i) % p) inv.append((-inv[p % i] * (p // i)) % p) factinv.append((factinv[-1] * inv[-1]) % p) ans = 0 for i in range(N): # N - 1 choose i 回寄与する ans += cmb(N - 1, i, p) * A[i] ans %= p print(ans)