def comb(n,r):
    ans = 1
    for i in range(r):
        ans *= n-i
    for i in range(r):
        ans //= i+1
    return ans
N = int(input())
A = list(map(int, input().split()))
ans = 0
mod = 10**9+7
for i in range(N):
    ans += A[i]*comb(N-1,i)%mod
    ans %= mod
print(ans)