#include <bits/stdc++.h>
#include <atcoder/all>
typedef long long int ll;
#define REP(i, n) for (ll i = 0; i < signed(n); i++)
using namespace atcoder;
using namespace std;
int main() {
  ll N, M, T;
  cin >> N >> M >> T;
  assert(1 <= N && N <= 200000);
  assert(1 <= M && M <= 200000);
  assert(1 <= T && T <= 1000000000);
  vector<ll> A(N);
  REP (i, M) {
    ll x;
    cin >> x;
    assert(1 <= x && x <= N);
    A[x - 1]++;
  }
  ll ok = 1e9, ng = 0;
  auto judge = [&](ll mid) {
    ll sum = 0;
    REP (i, N) {
      if (A[i] <= mid) {
        sum += A[i] + (mid - A[i]) / T;
      } else {
        sum += mid;
      }
    }
    return M <= sum;
  };
  while (abs(ok - ng) > 1) {
    ll mid = (ok + ng) / 2;
    if (judge(mid))
      ok = mid;
    else
      ng = mid;
  }
  cout << ok << endl;
  return 0;
}