#include <algorithm>
#include <iostream>
#include <cstdio>
#include <map>
#include <numeric>
#include <cmath>
#include <set>
#include <sstream>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <complex>
#include <string.h>
#include <unordered_set>
#include <unordered_map>
#include <iomanip>
using namespace std;

#define endl '\n'
#define all(v) (v).begin(), (v).end()
#define rall(v) (v).rbegin(), (v).rend()
#define uniq(v) (v).erase(unique((v).begin(), (v).end()), (v).end())

typedef long long ll;
typedef pair<int, int> P;
typedef unsigned int uint;
typedef unsigned long long ull;
struct pairhash {
public:
    template<typename T, typename U>
    size_t operator()(const pair<T, U> &x) const {
	size_t seed = hash<T>()(x.first);
	return hash<U>()(x.second) + 0x9e3779b9 + (seed<<6) + (seed>>2);
    }
};

const int inf = 1000000009;
const double eps = 1e-8;

ll solve(int n, ll d, ll t) {
    ll buf = (ll)1e9;
    unordered_map<ll, vector<ll> > xs;
    for (int i = 0; i < n; i++) {
	ll x;
	scanf("%lld", &x);
	ll m = (x + buf) % d;
	if (xs.count(m) == 0) {
	    vector<ll> vec;
	    vec.push_back(x);
	    xs[m] = vec;
	} else {
	    xs[m].push_back(x);
	}
    }

    ll res = n;
    for (auto& p : xs) {
	sort(all(p.second));
	res += 2 * t;
	for (int i = 0; i < p.second.size() - 1; i++) {
	    res += min(2*t, (p.second[i+1]-p.second[i])/d-1);
	}
    }
    return res;
}

int main() {
    /*
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout << fixed << setprecision(15);
    */

    int n;
    ll d, t;
    scanf("%d%lld%lld", &n, &d, &t);
    printf("%lld\n", solve(n, d, t));
}