#include<algorithm>
#include<fstream>
using namespace std;
ifstream f("zombie.in"); ofstream g("zombie.out");
int a[1000001];
int main()
{   int n,d,k,last,i,first=1,nr=0;
    f>>d>>n>>k;
    for(i=1;i<=n;i++) f>>a[i];
    for(last=2;last<=n;last++)
         if(a[last]-a[first]>=d)
        nr+=min(last-first,k),first=last;
    nr+=min(last-first,k);
    g<<nr<<'\n'; return 0;
}