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

int main() {
    ll N, D, T, X[110];
    cin >> N >> D >> T;
    for (int i = 0; i < N; i++) {
        cin >> X[i];
    }

    map<int, priority_queue<pair<ll, ll>>> V;
    for (int i = 0; i < N; i++) {
        V[(X[i] % D + D) % D].push({X[i] - D * T, X[i] + D * T});
    }

    ll ans = 0;
    for (auto& tmp : V) {
        auto& que = tmp.second;
        while (!que.empty()) {
            auto p = que.top();
            que.pop();
            if (!que.empty() && p.first <= que.top().second) {
                p.first = que.top().first;
                que.pop();
                que.push(p);
            } else {
                ans += (p.second - p.first) / D + 1;
            }
        }
    }
    cout << ans << endl;
}