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



int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int w, n;
    cin >> n >> w;

    vector<int> a(13);
    for (int i = 0; i < n; ++i) {
        int x;
        cin >> x;
        x--;
        a[x]++;
    }

    vector<int> sum(1 << 13);
    for (int i = 1; i < (1 << 13); ++i) {
        int x = i & -i;
        sum[i] += sum[i - x] + a[__lg(x)];
    }

    const int INF = 1e9;
    vector<int> f(1 << 13, INF);
    f[0] = 0;
    for (int i = 1; i < (1 << 13); ++i) {
        for (int j = i - 1;; j = (j - 1) & i) {
            if (sum[i - j] <= w) {
                f[i] = min(f[i], f[j] + 1);
            }
            if (j == 0) {
                break;
            }
        }
    }
    cout << f[(1 << 13) - 1] << '\n';
    return 0;
}