#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>    // 包含 tree、gp_hash_table、cc_hash_table
#include <ext/pb_ds/priority_queue.hpp> // 引入后使用 STL 的堆需要 std::
#include <ext/rope>
using namespace __gnu_pbds;
using namespace __gnu_cxx;
using namespace std;
template<typename key, typename val = null_type, typename cmp = less<>>
using rb_tree = tree<key, val, cmp, rb_tree_tag, tree_order_statistics_node_update>;
template<typename key, typename cmp = less<>>
using pairing_heap = __gnu_pbds::priority_queue<key, cmp>;
typedef long long ll;
#define int long long
mt19937_64 rd(time(0));

const int mod = 1e9 + 7;

auto binpow = [](int a, int b, int res = 1) {
    for (a %= mod; b; b >>= 1, (a *= a) %= mod) {
        if (b & 1) (res *= a) %= mod;
    }
    return res;
};

void QAQ() {
    int n, k;
    cin >> n >> k;

    vector<int> a(n + 1);

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

    sort(a.begin() + 1, a.end());

    int l = 0, r = k;

    vector<int> ta(n + 1);

    auto chk = [&](int mid) {
        int sum = mid;
        for (int i = 2; i <= n; i++) {
            ta[i] = (a[i] - a[i - 1] + 1) / 2;
            ta[i] = max<int>(0, mid - ta[i]);
            sum += ta[i];
        }
        return sum;
    };

    while (l < r) {
        int mid = l + r + 1 >> 1;
        if (chk(mid) <= k) {
            l = mid;
        } else {
            r = mid - 1;
        }
    }

    int tmp = k - chk(l);

    for (int i = 1; tmp; tmp--, i++) {
        (a[i] *= 2) %= mod;
    }

    int ans = a[1] * binpow(2, l) % mod;

    for (int i = 2; i <= n; i++) {
        (ans += a[i] * binpow(2, ta[i]) % mod) %= mod;
    }

    cout << ans << "\n";
}

signed main() {
    cin.tie(0) -> sync_with_stdio(0);
    int t = 1;
    // cin >> t;

    while (t--) {
        QAQ();
    }
}