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

#define F first
#define S second

typedef long long ll;

const int inf = 1e9;

int n, w, c[14], dp[1 << 14];

int main() {
    ios_base::sync_with_stdio(0), cin.tie(0);
    cin >> n >> w;
    for (int i = 1, x; i <= n; ++i) {
        cin >> x;
        c[x - 1]++;
    }
    int k = 13;
    vector<int> can;
    for (int i = 1; i < (1 << k); ++i) {
        int p = 0;
        for (int j = 0; j < 13; ++j) {
            if ((i >> j) & 1) {
                p += c[j];
            }
        }
        if (p <= w) {
            can.push_back(i);
        }
        dp[i] = inf;
    }
    for (int i = 0; i < (1 << k); ++i) {
        for (auto j : can) {
            dp[i | j] = min(dp[i | j], dp[i] + 1);
        }
    }
    cout << dp[(1 << k) - 1] << '\n';
}