#include <bits/stdc++.h>
using namespace std;
#define int long long
const int inf = 0x3f3f3f3f3f3f3f3f;

const int N = 2e5 + 10;
const int mod = 1e9 + 7;
int a[N];

int powmod(int a, int b) {
  int res = 1;
  for (; b; b >>= 1) {
    if (b & 1) res = res * a % mod;
    a = a * a % mod;
  }
  return res;
}
 
void solve() {
  int n, k;
  cin >> n >> k;
  priority_queue<int> q;
  for (int i = 1; i <= n; i++) {
    cin >> a[i];
    q.push(-a[i]);
  }

  int Limit = 1ll << 32;
  while (k && -q.top() < Limit) {
    auto t = q.top();
    q.pop();
    q.push(t * 2);
    k--;
  }
  for (int i = 1; i <= n; i++) {
    a[i] = -q.top();
    a[i] %= mod;
    q.pop();
  }
  int ans = 0;
  for (int i = 1; i <= n; i++) {
    if (k) a[i] = powmod(2, n / k) * a[i] % mod * (i <= n % k ? 2 : 1) % mod;
    ans = (ans + a[i] % mod);
    assert(ans >= 0);
  }
  cout << ans << '\n';
}

signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int _ = 1;
  // cin >> _;
  while (_--) {
    solve();
  }
  return 0;
}