#include <iostream>
#include <fstream>
#include <queue>
using namespace std;

const int dim = 1<<20;
int D, N, K, C, V[dim];

int main()
{
    ifstream cin ("zombie.in");
    ofstream cout ("zombie.out");

    cin >> D >> N >> K;
    for (int i = 1; i <= N; i++)
    {
        cin >> V[i];
    }

    int p = 1;
    for (int i = 1; i <= N; i++)
    {
        if (V[i] - V[p] < D) continue;
        if (i - p >= K)
        {
            p = i;
            C += K;
        }
        else
        {
            p++;
            C++;
        }
    }
    if (N - p >= K)
        C += K;
    else
        C += N - p + 1;

    cout << C;

    return 0;
}