#include <algorithm>
#include <iostream>

using namespace std;

long long N, D, T;
long long X[100];
bool finished[100];

int main() {
	cin >> N >> D >> T;
	for (int i = 0; i < N; i++) {
		cin >> X[i];
	}
	sort(X, X + N);
	long long res = 0;
	for (int i = 0; i < N; i++) {
		if (finished[i]) {
			continue;
		}
		finished[i] = true;
		long long mi0 = X[i] - D * T, ma0 = X[i] + D * T;
		for (int j = i + 1; j < N; j++) {
			if ((D + X[i] % D) % D != (D + X[j] % D) % D) {
				continue;
			}
			finished[j] = true;
			long long mi = X[j] - D * T, ma = X[j] + D * T;
			if (ma0 < mi) {
				res += (ma0 - mi0) / D + 1;
				mi0 = mi; ma0 = ma;
			} else {
				ma0 = ma;
			}
		}
		res += (ma0 - mi0) / D + 1;
	}
	cout << res << endl;
	return 0;
}