#include <fstream>

int min(int a, int b) {
	return a < b ? a : b;
}

std::ifstream fin("zombie.in");
std::ofstream fout("zombie.out");

long long N, D, K, x, counter, sum, start;

int main() {
	fin >> D >> N >> K;
	
	fin >> start;
	for (int i = 2; i <= N; ++i) {
		fin >> x;
		
		if (x - start < D) {
			++counter;
		} else {
			sum += min(counter, K);
			
			start = x;
			counter = 0;
			
		}
	}
	
	sum += min(counter, K);
	
	fout << sum << '\n';
	
	return 0;
}