#include <bits/stdc++.h>
using namespace std;
int main() {
	int N, C, K;
	cin >> N >> C >> K;
	vector<int> T(N);
	for (auto& x : T) cin >> x;
	sort(T.begin(), T.end());
	int r = 0;
	int n = 0, s = -1;
	for (auto x : T) {
		if (n == 0 || s + K < x || n == C) {
			n = 1;
			s = x;
			++ r;
		} else {
			++ n;
		}
	}
	cout << r << endl;
}
