#include using namespace std; int main() { long long N, i; cin >> N; long long N2 = N / 2; long long a[100001]; long long b[100001]; long long ans = 0; b[0] = 1; for (i = 1; i < N2+1; ++i) { b[i] = b[i-1]*(N-i)/i; } for (i = 0; i < N; ++i) { cin >> a[i]; } for (i = 0; i < N2; ++i) { ans += (a[i]+a[N-1-i])*b[i]; ans %= 1000000007; } if (N%2 == 1) { ans += a[N2]*b[N2]; } cout << ans % 1000000007 << " " << endl; }