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

#define rep(i, a, b) for(int i = a; i < (b); ++i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;

int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);

  const int k = 13;
  int n, W;
  cin >> n >> W;
  vi a(n);
  array<int, k> c = {0};
  for (auto&x : a) {
    cin >> x;
    c[x-1]++;
  }
  const int INF = 1e9;
  vector<int> dp(1<<k, INF);
  for (int mask = 0; mask < (1<<k); mask++) {
    int sum = 0;
    rep(b, 0, 13) {
      if (mask>>b&1)
        sum += c[b];
    }
    if (sum <= W) {
      dp[mask] = (sum == 0?0:1);
      continue;
    }
    for (int sub = mask; sub; sub = (sub-1)&mask) {
      int other = mask^sub;
      dp[mask] = min(dp[mask], dp[sub] + dp[other]);
    }
  }
  cout << dp[(1<<k) - 1] << '\n';
}
// 13 numbers, each time you can take a subset whose sum <= W
// How many times to choose?