from math import factorial

N = int(input())
A = list(map(int,input().split()))


z = factorial(N-1) % (10**9+7)

ans = A[0] + A[-1]

for i in range(1,N-1) :
    x = math.factorial(i) % (10**9+7)
    y = math.factorial(N-1-i) % (10**9+7)
    xy = (x*y) % (10**9+7)
    comb = z//(x*y)
    ans += comb*A[i]
print(ans)