#include <cstdio>
using namespace std;
const int NMAX = 1000005;
int v[NMAX];

int main() {
  int d, n, k;
  freopen("zombie.in", "r", stdin);
  freopen("zombie.out", "w", stdout);
  scanf("%d%d%d", &d, &n, &k);
  for(int i = 1; i <= n; i++) {
    scanf("%d", &v[i]);
  }
  int sol = 0;
  for(int i = 1; i <= n; ) {
    int j = i + 1;
    while(j <= n && v[i] + d - 1 >= v[j]) {
      j++;
    }
    if(j - i + 1 > k) {
      sol += k;
    }
    else {
      sol += (j - i);
    }
    i = j;
  }
  printf("%d\n", sol);
  return 0;
}