#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <sstream>
#include <cstring>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <numeric>
#include <cctype>
#include <tuple>
#include <array>
#include <climits>
#include <bitset>
#include <cassert>

#ifdef _MSC_VER
#include <agents.h>
#endif

#define FOR(i, a, b) for(int i = (a); i < (int)(b); ++i)
#define rep(i, n) FOR(i, 0, n)
#define ALL(v) v.begin(), v.end()
#define REV(v) v.rbegin(), v.rend()
#define MEMSET(v, s) memset(v, s, sizeof(v))
#define UNIQUE(v) (v).erase(unique(ALL(v)), (v).end())
#define MP make_pair
#define MT make_tuple

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int, int> P;

int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	cout.setf(ios::fixed);
	cout.precision(20);

	ll n, d, t;
	cin >> n >> d >> t;

	vector<int> x(n);
	rep(i, n) cin >> x[i];

	map<int, pair<ll, ll>> m;

	rep(i, n){
		ll y = x[i] % d;
		if (y < 0) y += d;
		if (!m.count(y)) m[y] = MP(x[i] - d*t, x[i] + d*t);
		else{
			m[y].first = min(m[y].first, x[i] - d*t);
			m[y].second = max(m[y].second, x[i] + d*t);
		}
	}

	ll ans = 0;
	for (auto it : m){
		auto p = it.second;
		ans += (p.second - p.first) / d + 1;
	}
	cout << ans << endl;
}