// yukicoder: No.797 Noelちゃんとピラミッド
// 2019.5.6 bal4u

#include <stdio.h>

//// 高速入力
#if 1
#define gc() getchar_unlocked()
#else
#define gc() getchar()
#endif
int in()    // 非負整数の入力
{
	int n = 0, c = gc();
	//	while (isspace(c)) c = gc();
	do n = 10 * n + (c & 0xf), c = gc(); while (c >= '0');
	return n;
}

#define M 1000000007
#define MAX 100000

long long fact[MAX+2], inv[MAX+2], factinv[MAX+2];

long long comb(int n, int k)
{
    if (n < 0 || k < 0 || n < k) return 0;
	if (k == 0) return 1LL;
    return (((fact[n] * factinv[k]) % M) * factinv[n-k]) % M;
}

int main()
{
	int i, N;
	long long s = 0;
	
	for (fact[0] = 1, i = 1; i <= MAX; i++) fact[i] = (fact[i-1]*i) % M;
	for (inv[1]  = 1, i = 2; i <= MAX; i++) inv[i] = (M + (-(M/i)*inv[M % i]) % M) % M;
	for (factinv[0] = 1, i = 1; i <= MAX; i++) factinv[i] = (factinv[i-1]*inv[i]) % M;
	
	N = in();
	if (N <= 2) {
		while (N--) s += in();
	} else {
		N--;
		for (i = 0; i <= N; i++) s += (comb(N, i)*in()) % M;
	}
	printf("%d\n", (int)(s % M));
	return 0;
}