#include <bits/stdc++.h>
using namespace std;
int main()
{
    cin.tie(0)->sync_with_stdio(0);
    int n, w;
    cin >> n >> w;
    vector<int> a(n);
    const int M = 13;
    vector<int> cnt(M), sum(1 << M), dp(1 << M, M + 1);
    for (auto &i : a)
        cin >> i, cnt[i - 1]++;
    for (int i = 0; i < 1 << M; i++)
    {
        for (int j = 0; j < M; j++)
            if ((i >> j) & 1)
                sum[i] += cnt[j];
    }
    dp[0] = 0;
    for (int i = 1; i < 1 << M; i++)
    {
        for (int j = i; j; j = (j - 1) & i)
        {
            if (sum[j] <= w)
                dp[i] = min(dp[i], 1 + dp[i ^ j]);
        }
        // cout << i << " " << dp[i] << endl;
    }
    cout << dp.back() << endl;
}