#include <bits/stdc++.h>

using namespace std;

int main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);

  int n;
  long long d, t;
  cin >> n >> d >> t;

  vector<long long> x(n);
  for (int i = 0; i < n; i++)
    cin >> x[i];

  set<long long> mod;
  for (int i = 0; i < n; i++)
    mod.insert((x[i] % d + d) % d);

  long long ret = 0;
  for (long long m: mod) {
    vector<long long> y;
    for (int i = 0; i < n; i++)
      if ((x[i] % d + d) % d == m)
        y.push_back(x[i]);

    sort(y.begin(), y.end());
    vector<pair<long long, long long> > v;
    for (int i = 0; i < y.size(); i++) {
      long long l = y[i] - d * t;
      long long r = y[i] + d * t;
      if (v.empty())
        v.emplace_back(l, r);
      else if (l <= v.back().second)
        v.back().second = max(v.back().second, r);
      else
        v.emplace_back(l, r);
    }

    for (auto &pr: v) {
      ret += (pr.second - pr.first) / d + 1;
    }
  }

  cout << ret << endl;
  
  return 0;
}