#include<fstream>
#include <algorithm>
using namespace std;

int i, N, D, K;
int x, nr, P;
int ANS;
  
int main() {
	freopen("zombie.in","r",stdin);
	freopen("zombie.out","w",stdout);
	scanf("%i%i%i", &D, &N, &K);
    for(i = 1; i <= N; ++i) {
        scanf("%i", &x);
        if(nr) {
            if (P + D > x) 
				++nr;
			else {
				ANS += min(nr, K); 
				P = x; 
				nr = 1;
			}
        }
        else 
			nr = 1, 
			P = x;
    }
    if(nr) 
		ANS += min(nr, K);
	printf("%i\n", ANS);
    return 0;
}