#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vs = vector<string>;
using vp = vector<pair<int, int>>;

#define rep(i, s, n) for (int i = s; i < (int)(n); i++)
#define sz(x) ((int)(x).size())
constexpr int INFI = 1001001001;
constexpr ll INFL = (1LL << 60);

ll binary_search(ll n, ll t, vl cnt) {
  ll ng = -1; 
  ll ok = INFL; 

  while (ok - ng > 1) {
    ll mid = ng + (ok - ng) / 2;
		ll res = 0;
		// cerr <<"mid: "<< mid << "\n" ;
		rep (i, 1, n + 1){
			ll st = cnt[i] - mid;
			if(st > 0) res += st;
			else{
				res += st / t;
			}
			// cerr <<"cnt[i]: "<< cnt[i] <<" st: "<< st << "\n" ;
		}
    if (res <= 0) ok = mid;
    else ng = mid;
  }  
  return ok;
}

int main (){
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	// input
	ll n, m, t;
	cin >> n >> m >> t;
	vl cnt (n + 1, 0);
	rep(i, 0, m){
		int a;
		cin >> a;
		cnt[a] ++;
	}

	ll ok = binary_search(n, t, cnt);
	cout << ok << endl;
	
	return 0;
}