#include <fstream>
using namespace std;

int main()
{ int d,n,k,i,nr,sol=0,st,x;
    ifstream f("zombie.in");
    ofstream g("zombie.out");
    f>>d>>n>>k;
    f>>st;
    nr=1;
    for (i=2;i<=n;++i) {
        f>>x;
        if (x-st<d) ++nr;
        else {
          sol+=min(nr,k);
          nr=1;
          st=x;
         }
    }
      sol+=min(nr,k);
      g<<sol;
    return 0;
}