#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi  = vector<int>; using vb  = vector<bool>; using vd  = vector<double>; using vl  = vector<ll>;
using vvi = vector<vi>;  using vvb = vector<vb>;   using vvd = vector<vd>;     using vvl = vector<vl>;

#define REP(i,n) for(ll i=0; i<(n); ++i)
#define FOR(i,b,n) for(ll i=(b); i<(n); ++i)
#define ALL(v) (v).begin(), (v).end()
#define TEN(x) ((ll)1e##x)

int main() {
	ll n, d, t;
	cin >> n >> d >> t;
	vl x(n);
	for (auto&&i : x) cin >> i;

	vb visited(n, false);
	vvl unions;
	REP(i, n) if(!visited[i]) {
		vl u = { x[i] };
		visited[i] = true;
		FOR(j, i + 1, n) if (abs(x[i] - x[j]) % d == 0) {
			u.push_back(x[j]);
			visited[j] = true;
		}
		unions.push_back(u);
	}

	REP(i, unions.size()) sort(ALL(unions[i]));

	vvl dist(unions.size());
	REP(i, unions.size()) FOR(j, 1, unions[i].size()) dist[i].push_back(unions[i][j] - unions[i][j-1]);
	REP(i, dist.size()) sort(ALL(dist[i]));
	
	ll sum = n;
	REP(i, dist.size()) {
		ll prev = 0;
		REP(j, dist[i].size()) {
			ll td = dist[i][j] / (2 * d);
			sum += (min(t,td) - prev) * 2 * (dist[i].size() - j + 1) - (td <= t && dist[i][j] % (2 * d) == 0 ? 1 : 0);
			prev = td;
			if (prev > t) break;
		}
		if (prev<t) sum += (t - prev) * 2;
	}

	cout << sum << endl;

	return 0;
}