//Author: Kevin
#include<bits/stdc++.h>
//#pragma GCC optimize("O2")
using namespace std;
#define ll long long
#define ull unsigned ll
#define pb emplace_back
#define mp make_pair
#define ALL(x) (x).begin(),(x).end()
#define rALL(x) (x).rbegin(),(x).rend()
#define srt(x) sort(ALL(x))
#define rev(x) reverse(ALL(x))
#define rsrt(x) sort(rALL(x))
#define sz(x) (int)(x.size())
#define inf 0x3f3f3f3f
#define pii pair<int,int>
#define lb(v,x) (int)(lower_bound(ALL(v),x)-v.begin())
#define ub(v,x) (int)(upper_bound(ALL(v),x)-v.begin())
#define uni(v) v.resize(unique(ALL(v))-v.begin())
#define longer __int128_t
void die(string S){puts(S.c_str());exit(0);}
int cnt[13];
int dp[(1<<13)];
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	int n,w;
	cin>>n>>w;
	while(n--)
	{
		int x;
		cin>>x;
		cnt[x-1]++;
	}
	memset(dp,0x3f,sizeof(dp));
	dp[0]=0;
	for(int i=0;i<(1<<13);i++)
	{
		int rm=(1<<13)-1-i;
		for(int j=rm;j;j=(j-1)&rm)
		{
			int sum=0;
			for(int x=0;x<13;x++)
				if(j>>x&1)
					sum+=cnt[x];
			if(sum<=w)
				dp[i|j]=min(dp[i|j],dp[i]+1);
		}
	}
	cout<<dp[(1<<13)-1]<<endl;
	return 0;
}