/*
60 + 0 + 100 + 64 = 224.
*/

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define L(i, j, k) for (int i = (j); i <= (k); i++)
#define R(i, j, k) for (int i = (j); i >= (k); i--)
#define pb push_back
#define pii pair<int, int>
inline int read()
{
	int sum = 0, nega = 1;
	char ch = getchar();
	while (ch > '9'||ch < '0')
	{
	    if (ch == '-') nega = -1;
		ch = getchar();
	}
	while (ch <= '9' && ch >= '0') sum = sum * 10 + ch - '0', ch = getchar();
	return sum * nega;
}
const int N = (1 << 13) + 9, mod = 998244353;
inline void add(int &x, int y) {x = (x + y) % mod;}
inline void del(int &x, int y) {x = (x - y + mod) % mod;}
int n, w, cnt[15], dp[N], t = 13;
signed main()
{
	n = read(), w = read();
	L(i, 0, (1 << t) - 1) dp[i] = 1e9;
	dp[0] = 0;
	L(i, 1, n)
	{
		int x = read();
		cnt[x - 1]++;
	}
	L(i, 1, (1 << t) - 1)
	{
		for (int S = i; S; S = (S - 1) & i)
		{
			int r = 0;
			L(j, 0, t - 1)
				if(S & (1 << j)) r += cnt[j];
			if(r > w) continue;
			dp[i] = min(dp[i], dp[i ^ S] + 1);
		}
	}
	cout << dp[(1 << t) - 1] << endl;
	return 0;
}