#include <iostream>
#include <fstream>
using namespace std;
ifstream fin("zombie.in");
ofstream fout("zombie.out");
int main()
{
    int d, n, k, i, minn, nr, s=0, a;
    fin >> d >> n >> k;
    fin >> a;
    minn=a; nr=1;
    for(i=2; i<=n; i++)
    {
        fin >> a;
        if(a-minn+1>=d)
        {
            if(nr<=k)  s+=nr;
            else s+=k;
            nr=1;
            minn=a;
        }
        else nr++;

    }
     if(nr<=k)  s+=nr;
    else s+=k;
    fout << s;
    return 0;
}