#include <fstream>
using namespace std;
ifstream fin ("zombie.in");
ofstream fout ("zombie.out");
int D, N, K, nr, t, p, sol, V[1000010];

int main()
{
    fin >> D >> N >> K;
    for (int i = 1; i <= N; i++) fin >> V[i];
    p = 1;
    t = 1;
    for (int i = 2; i <= N; i++)
    {
        if (V[i] - V[p] > N)
        {
            if (i - p > K) sol += K;
            while (V[i] - V[p] > D) p++, sol++;
        }
    }

    sol += min (N - p, K);
    fout << sol << '\n';
    fout.close();
    return 0;
}