# include <cstdio>

const char *FIN = "zombie.in", *FOU = "zombie.out";

int D, N, K, V[1000005];

int main (void) {
    freopen (FIN, "r", stdin);

    scanf ("%d %d %d", &D, &N, &K);
    for (int i = 1; i <= N; ++i)
        scanf ("%d", V + i);
    int sol = 0;
    for (int i = 1; i <= N; ) {
        int z = i++;
        for (; V[i] <= V[z] + D - 1; ++i);
        sol += (i - z >= K ? K : i - z);
    }
    fprintf (fopen (FOU, "w"), "%d", sol);
}