#include <fstream>

using namespace std;

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

const int MAX_ZOMBIES = 1e6;
int rasengan, zombies, answer, dist, first = 1;
int a[MAX_ZOMBIES + 2];

int main() {
    in >> dist >> zombies >> rasengan;
    for (int i = 1; i <= zombies + 1; ++i) {
        in >> a[i];
        if (a[first] + dist < a[i] || i == zombies + 1) {
            if (i - first >= rasengan) {
                answer += rasengan;
            } else {
                answer += (i - first);
            }
            first = i;
        }
    }
    out << answer << "\n";
    return 0;
}