#include <bits/stdc++.h>
using namespace std;
using i64 = int64_t;
using f64 = double_t;

int main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  int n, w;
  cin >> n >> w;
  vector<int> c(13);
  for (int i = 0, a; i < n; i += 1) {
    cin >> a;
    c[a - 1] += 1;
  }
  vector<int> sum(1 << 13), dp(1 << 13);
  for (int i = 1; i < (1 << 13); i += 1) {
    for (int j = 0; j < 13; j += 1) {
      if ((i >> j) % 2) { sum[i] += c[j]; }
    }
    dp[i] = numeric_limits<int>::max();
    for (int j = i; j; j = (j - 1) & i) {
      if (sum[j] <= w) { dp[i] = min(dp[i], dp[i ^ j] + 1); }
    }
  }
  cout << dp.back();
}