#include<iostream>
#include<fstream>
#include<sstream>
#include<string>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<ctime>
#include<stack>
#include<queue>
#include<set>
#include<map>
#include<vector>
#include<list>
#include<algorithm>
#include<utility>
#include<complex>
#include<functional>

using namespace std;

#define LL long long
LL l[100];
LL r[100];
LL type[100];

LL D, T, X;
vector < list<int> > adj(100);
LL bfs(int v){
	if (type[v] < 0)return 0;
	LL right = r[v];
	LL left = l[v];
	type[v] = -1;
	queue<int> que;
	que.push(v);

	while (que.empty() == false){
		v = que.front(); que.pop();
		right = max(right, r[v]);
		left = min(left, l[v]);
		for (auto& u  : adj[v]){
			if (type[u] < 0)continue;
			que.push(u);
			type[u] = -1;
		}
	}

	return (right - left) / D + 1;
}
int main(void){
	int N;
	cin >> N >> D >> T;

	for (int i = 0; i < N; i++){
		cin >> X;
		l[i] = X - D*T;
		r[i] = X + D*T;
		type[i] = r[i] % D;
	}
	for (int i = 0; i < N; i++)
		for (int j = i + 1; j < N; j++)
			if (type[i] == type[j] && (-min(l[i], l[j]) + max(r[i], r[j]) <= r[i] - l[i] + r[j] - l[j])){
				adj[i].push_back(j);
				adj[j].push_back(i);
			}
	LL res = 0;
	for (int i = 0; i < N; i++){
		res += bfs(i);
	}
	cout << res << endl;

	return 0;
}