#include <bits/stdc++.h>
using namespace std;

int minimumTransactions(int N, int X, vector<int> &B)
{

    priority_queue<int> pq;
    for (int i = 0; i < N; i++)
    {
        pq.push(B[i]);
    }

    int res = 0;

    while (pq.top() != 0 && X > 0)
    {
        int temp = pq.top();
        pq.pop();
        X -= temp;
        res++;
        pq.push(temp / 2);
    }

    if (X > 0)
    {
        return -1;
    }
    return res;
}

int main()
{
    int N, X;
    cin >> N >> X;

    vector<int> B(N);
    for (int i = 0; i < N; i++)
    {
        cin >> B[i];
    }
    cout << minimumTransactions(N, X, B) << endl;
}