#include <bits/stdc++.h>

//using namespace std;

using LL = long long;
using i128 = __int128;
constexpr int N = 1E5 + 10;
constexpr int mod = 1E9 + 7;
using std::cin;
using std::cout;
using std::vector;
using std::cerr;
using std::pair;

struct modint {
    LL x;
    modint (LL _x = 0) : x(_x % mod) {}
    modint operator+(const modint &p) const {
        LL res = x + p.x;
        while (res >= mod) res -= mod;
        return res;
    }
    modint operator*(const modint &p) const {
        return x * p.x % mod;
    }
};
using mint = modint;

mint p[N] = {};

int init = []() {
    p[0] = 1;
    for (int i = 1; i < N; i++) {
        p[i] = (p[i - 1] + p[i - 1]);
    }
    return 0;
}();



signed main() {
    cin.tie(nullptr) -> sync_with_stdio(false);
    int n, m;
    cin >> n >> m;

    mint sum = 0;
    auto get = [&](vector<int> &a) {
        __int128 s = 0, now = 0;
        for (int i = 1; i <= n; i++) {
            now += a[i];
            s += now;
        }
        vector<mint> f(m + 1);
        f[0] = s % mod;
        for (int i = 1; i <= m; i++) {
            f[i] = f[i - 1] + f[i - 1] + sum * p[i - 1] * p[i - 1] * n;
        }
        return pair(s, f);
    };

    vector<int> a(n + 1);
    for (int i = 1; i <= n; i++) {
        cin >> a[i];
        sum = sum + a[i];
    }

    auto [s1, f] = get(a);
    reverse(a.begin() + 1, a.end());
    auto [s2, g] = get(a);

    if (s1 >= s2) {
        cout << f[m].x << "\n";
    } else {
        cout << (f[m - 1] + g[m - 1] + sum * p[m - 1] * n * p[m - 1]).x << "\n";
    }

    return 0;
}