#include <bits/stdc++.h>
#define int long long

using namespace std;

constexpr int inf = 1E18;

void solve () {
    int n, W;
    cin >> n >> W;

    array <int, 14> sum {};
    for (int i = 0; i < n; i ++) {
        int x;
        cin >> x;
        sum[x] ++;
    }

    vector <int> a;
    for (int i = 1; i <= 13; i ++) {
        if (sum[i]) {
            a.push_back (sum[i]);
        }
    }

    n = a.size ();

    const int N = 1 << n;

    vector <int> dp (N, inf);
    dp[0] = 0;
    for (int s = 1; s < N; s ++) {
        for (int ns = (s - 1) & s; ; ns = (ns - 1) & s) {
            int sum = 0;
            for (int j = 0; j < n; j ++) {
                if (s >> j & 1 && ns >> j & 1 ^ 1) {
                    sum += a[j];
                }
            }
            if (sum <= W) {
                dp[s] = min (dp[s], dp[ns] + 1);
            }
            if (ns == 0) {
                break;
            }
        }
    }

    cout << dp.back () << '\n';
}

signed main () {
    ios::sync_with_stdio (false);
    cin.tie (nullptr);

    int T = 1;
    // cin >> T;

    while (T --) {
        solve ();
    }

    return 0;
}