#include <iostream>
#include <fstream>

using namespace std;

ifstream fin("zombie.in");
ofstream fout("zombie.out");

int d,n,k,nr;
int a[1000001];

int main()
{
    int i,j=1;
    fin>>d>>n>>k;
    for (i=1; i<=n; ++i) fin>>a[i];
    for (i=2; i<=n; ++i)
        if (a[i]-a[j]>=d) {
            nr+=min(i-j,k);
            j=i;
        }
    nr+=min(i-j,k);
    fout<<nr;
    return 0;
}