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

p = 10 ** 9 + 7
N = int(input())  # N は必要分だけ用意する
fact = [1, 1]
factinv = [1, 1]
inv = [0, 1]
 
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)

A = list(map(int,input().split()))
n = N-1
ans = 0
x = 1
for i in range(N):
  ans += A[i]*x
  ans %= p
  x = cmb(n,i+1,p)
print(ans)