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

C = [1]

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

ans = 0

for a,c in zip(A,C) :
    ac = a*c
    ac %= 10**9+7
    ans += ac
ans %= 10**9+7
print(ans)