#include <iostream>
#include <iomanip>
#include <string>
#include <vector>
#include <algorithm>
#include <math.h>
using namespace std;
typedef unsigned int uint;
typedef unsigned long ul;
typedef unsigned long long ull;
typedef long long ll;
typedef long double ld;
#define PI 3.1415926535897932384626433
int main()
{
ull output = 0;
ull n = 0, multiplier = 0;
std::cin >> n;
vector<ull> inputs;
for (ull i = 0; i < n; i++)
{
ull a = 0;
std::cin >> a;
inputs.push_back(a);
}
for (ull i = 0; i < n; i++)
{
multiplier += powl(2, i);
}
multiplier /= n;
for (ull i = 0; i < n; i++)
{
output += inputs[i] * multiplier;
}
output = output % 1000000007;
std::cout << output << "\n";
int w;
std::cin >> w;
return 0;
}