#include<bits/stdc++.h>
#define fore(i,l,r)	for(int i=(int)(l);i<(int)(r);++i)
#define fi first
#define se second
#define endl '\n'
#define ull unsigned long long
#define ALL(v) v.begin(), v.end()
#define Debug(x, ed) std::cerr << #x << " = " << x << ed;

const int INF=0x3f3f3f3f;
const long long INFLL=1e18;

typedef long long ll;

int main(){
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    std::cout.tie(nullptr);
	int n, w;
	std::cin >> n >> w;
	std::vector<int> c;
	std::vector<int> cnt(13);
	fore(i, 0, n){
		int k;
		std::cin >> k;
		--k;
		++cnt[k];
	}
	std::vector<int> len;
	fore(l, 0, 13)
		if(cnt[l])
			len.push_back(cnt[l]);
	const int K = len.size();
	fore(s, 1, 1 << K){
		int m = 0;
		fore(i, 0, K)
			if(s >> i & 1)
				m += len[i];
		if(m <= w) c.push_back(s);
	}
	
	std::vector<int> dp(1 << K, INF);
	dp[0] = 0;
	fore(s0, 0, 1 << K){
		for(auto x : c)
			dp[s0 | x] = std::min(dp[s0 | x], dp[s0] + 1);
	}
	
	
	std::cout << dp[(1 << K) - 1];
    
    return 0;
}