n = int(input()) alst = list(map(int, input().split())) MOD = 10 ** 9 + 7 fact = [0 for _ in range(n)] invfact = [0 for _ in range(n)] fact[0] = 1 for i in range(1, n): fact[i] = fact[i - 1] * i % MOD invfact[n - 1] = pow(fact[n - 1], MOD - 2, MOD) for i in range(n - 2, -1, -1): invfact[i] = invfact[i + 1] * (i + 1) % MOD def nCk(n, k): if k < 0 or n < k: return 0 else: return fact[n] * invfact[k] * invfact[n - k] % MOD ans = 0 for i, num in enumerate(alst): ans += nCk(n - 1, i) * num ans %= MOD print(ans)