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

#define SZ(a) (int)a.size()
#define ALL(a) a.begin(), a.end()
#define FOR(i, a, b) for (int i = (a); i<(b); ++i)
#define RFOR(i, b, a) for (int i = (b)-1; i>=(a); --i)
#define MP make_pair
#define PB push_back
#define F first
#define S second

typedef long long LL;
typedef pair<int, int> PII;
typedef vector<int> VI;

const int N = 104747;

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	int n, k;
	cin >> n >> k;
	
	vector<int> t(N);
	FOR (i, 0, n)
	{
		int a;
		cin >> a;
		t[a]++;
		t[a + 1000]--;
	}
	int cnt = 0;
	int ans = 0;
	FOR(i, 0, N)
	{
		cnt += t[i];
		ans = max(ans, cnt);
	}
	cout << (ans + k - 1) / k << '\n';
		
	return 0;
}