#include <fstream>
#define NMAX 1000000

using namespace std;

ifstream cin ("zombie.in");
ofstream cout ("zombie.out");

int v[NMAX + 1];

int main() {
  int d, n, k, i, st, dr, sol;
  cin >> d >> n >> k;

  for (i = 0; i < n; i++)
    cin >> v[i];

  st = dr = sol = 0;
  while (dr < n) {
    if (v[dr] <= v[st] + d)
      dr++;
    else {
      if (k < dr - st)
        sol += k;
      else
        sol += dr - st;
      st = dr;
    }
  }

  if (k < dr - st)
    sol += k;
  else
    sol += dr - st;

  cout << sol;
  return 0;
}