#include <fstream>
using namespace std;
ifstream f("zombie.in");
ofstream g("zombie.out");
unsigned long long  N, D, K, activeZ, st, sol, x;
int main()
{
    f >> D >> N >> K;
    for(int i = 1; i <= N; i++){
        f >> x;
        if(x - st <= D - 1){
            activeZ++;
            continue;
        }
      sol += activeZ > K ? K : activeZ;
      activeZ = 1;
      st = x;
    }
    sol += activeZ > K ? K : activeZ;
    g << sol;
    return 0;
}