#include <iostream>
#include <vector>
#include <algorithm>
#include <climits>

using namespace std;

int minNap(int n, int p, int db, int ossz, const vector<int>& v) {
    if (ossz >= p) {
        return db; // Base case: reached the target amount
    }
    if (n < 0) {
        return INT_MAX; // Base case: no more elements to add
    }
    // Recursively compute the minimal day by considering two choices:
    // 1. Include v[n] in the total and increment the day count
    // 2. Skip the current day
    int include = minNap(n - 1, p, db + 1, ossz + v[n], v);
    int exclude = minNap(n - 1, p, db, ossz, v);

    return min(include, exclude); // Return the minimum of both choices
}

int main() {
    int n, p;
    cin >> n >> p;
    vector<int> v(n);
    for (auto& i : v)
        cin >> i;

    int result = minNap(n - 1, p, 0, 0, v); // Start from the last element
    if (result == INT_MAX) {
        cout << -1 << endl; // Output -1 if it's impossible to reach the target
    } else {
        cout << result << endl; // Output the minimum number of days
    }
    return 0;
}