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

C = 1
x = 1
y = N-1

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

for i in range(1,N-1) :
    C = (C * y // x)
    x += 1
    y -= 1
    ans += A[i]*C
    ans %= 10**9+7
print(ans)