#include <bits/stdc++.h>
#define int long long

using namespace std;

const int mod = 1E9 + 7;

inline int read () {
    int w = 1, s = 0; char ch = getchar ();
    for (; ! isdigit (ch); ch = getchar ()) if (ch == '-') w = -1;
    for (; isdigit (ch); ch = getchar ()) s = (s << 1) + (s << 3) + (ch ^ 48);
    return s * w;
}

int power (int x, int p) {
    int ans = 1;
    for (; p; p >>= 1) {
        if (p & 1) ans = ans * x % mod;
        x = x * x % mod;
    }    
    return ans;
}

void solve () {
    int n, m;
    cin >> n >> m;

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

    const int N = power (2, m - 1);
    const int D = 2 * n;

    auto work = [&] (int a1) {
        return (a1 * N - N * (N - 1) / 2 % mod * D) % mod;
    };

    int ans = 0;

    for (int i = 1; i <= n; i ++) {
        ans += work ((N * D - 2 * n + (n - i + 1) + mod) % mod) * a[i];
        ans %= mod;
        // cerr << i << " " << ans << "\n";
        ans += work ((N * D - n + i + mod) % mod) % mod * a[i];
        ans %= mod;
        // cerr << i << " " << ans << "\n";
    }

    cout << ans << '\n';
} 

signed main () {
	ios::sync_with_stdio (false);
    cin.tie (nullptr);
    
	int T = 1; 
	// cin >> T;
	// T = read ();

	while (T --) {
		solve ();
	}
	
	return 0;
}