#include <fstream>

using namespace std;

int main() {
    ifstream fin("zombie.in");
    ofstream fout("zombie.out");
    int d,n,k,a,b,cnt,cost;
    fin>>d>>n>>k;
    fin>>b;
    cnt=1;
    cost=0;
    for(int i=1;i<n;i++) {
      fin>>a;
      if(d-(a-b)<0) {
        if(cnt<k)
          cost=cost+cnt;
        else
          cost=cost+k;
        cnt=1;
        b=a;
      }
      else {
        cnt++;
      }
    }
    if(cnt<k)
          cost=cost+cnt;
        else
          cost=cost+k;
    fout<<cost;
    return 0;
}