#include <stdio.h>

const long long mod = 1000000007;
long long comb[111][111];
int N;

int main()
{
	scanf ("%d", &N);
	for (int i = 0; i < N; i++){
		comb[i][0] = comb[i][i] = 1;
		for (int j = 1; j < i; j++){
			comb[i][j] = (comb[i - 1][j - 1] + comb[i - 1][j]) % mod;
		}
	}

	long long ans = 0;
	for (int i = 0; i < N; i++){
		int x; scanf ("%d", &x);
		ans = (ans + x * comb[N - 1][i]) % mod;
	}

	printf("%lld\n", ans);

	return 0;
}