#include <bits/stdc++.h>
using namespace std;

#define int long long

signed main(void) {
	int N, D, T;
	cin >> N >> D >> T;
	vector<int> X(N);
	for(int i = 0; i < N; ++i) cin >> X[i];
	
	map<int, vector<int>> m;
	for(int i = 0; i < N; ++i) m[X[i] % D].push_back(X[i] / D);
	
	int ans = 0;
	for(auto [_, v] : m) {
		sort(v.begin(), v.end());
		int M = v.size(), fr = v.front() - T;
		for(int i = 0; i < M - 1; ++i) {
			if(v[i] + T < v[i + 1] - T) {
				ans += (v[i] + T) - fr + 1;
				fr = v[i + 1] - T;
			}
		}
		ans += (v.back() + T) - fr + 1;
	}
	
	cout << ans << endl;
	return 0;
}