#include <bits/stdc++.h>

using i64 = long long;
using A2 = std::array<i64, 2>;

#define Fast_IOS std::ios::sync_with_stdio(false), std::cin.tie(0), std::cout.tie(0)

const i64 mod = 1e9 + 7;

template <class T>
T MOD(T& x, i64 p = mod) {
    return x = (x % p + p) % p;
}
template <class T>
T MOD(T&& x, i64 p = mod) {
    return x = (x % p + p) % p;
}

class WORK {
   public:
    int N;

    WORK() {}

    i64 qpow(i64 a, i64 b) {
        i64 res = 1;
        while (b) {
            if (b & 1) {
                res = res * a % mod;
            }
            a = a * a % mod;
            b >>= 1;
        }
        return res;
    }

    void solve() {
        int n, m;
        std::cin >> n >> m;
        std::vector<int> a(n + 1);
        i64 ans1 = 0, ans2 = 0, sum = 0;
        for (int i = 1; i <= n; i++) {
            std::cin >> a[i];
            ans1 += a[i];
            ans2 += a[i] * (n - i + 1);
            ans1 %= mod;
            ans2 %= mod;
            // sum += a[i] * n;
        }
        // i64 ans = 0;
        i64 sum1 = 2 * n + 1, sum2 = ans2;
        for (int i = 1; i < m; i++) {
            sum1 = (sum1 * 2 % mod + n * qpow(2, 2 * i) % mod) % mod;
        }
        sum1 = sum1 * ans1 % mod;
        i64 temp = ans1, p2 = n;
        for (int i = 0; i < m; i++) {
            sum2 = (sum2 * 2 % mod + temp * p2 % mod) % mod;
            temp = temp * 2 % mod;
            p2 = p2 * 2 % mod;
        }
        std::cout << std::max(sum1, sum2) % mod << '\n';
    }
};

int main() {
    Fast_IOS;
    WORK work;
    int T = 1;
    // std::cin >> T;
    while (T--) {
        work.solve();
    }
    return 0;
}