public class Solution {
    public int nchoc(int A, ArrayList<Integer> B) {
        TreeMap<Integer, Integer> bags = new TreeMap<Integer, Integer>();
        long res = 0;
        int mod = (int) (Math.pow(10, 9)) + 7;
        for (int i = 0; i < B.size(); i++) {
            int key = B.get(i);
            if (bags.containsKey(key)) {
                int val = bags.get(key) + 1;
                bags.put(key, val);
            }
            else
                bags.put(key, 1);
        }
        for (int i = 0; i < A; i++) {
            int chocos = bags.lastKey();
            int val = bags.get(chocos) - 1;
            if (val == 0)
                bags.remove(chocos);
            else
                bags.put(chocos/2, val);
            res = ((res%mod) + (chocos%mod))%mod;
        }
        return res%mod;
    }
}