from scipy.special import comb
N = int(input())
A = list(map(int,input().split()))
n = N-1
ans = 0
MOD = 10**9+7
x = 1
for i in range(N):
  ans += A[i]*x
  ans %= MOD
  x = comb(n,i+1,exact=True)
print(ans)