#include <bits/stdc++.h>
  
using namespace std;
  
#define rep(i,n) REP(i,0,n)
#define REP(i,s,e) for(int i=(s); i<(int)(e); i++)
#define repr(i, n) REPR(i, n, 0)
#define REPR(i, s, e) for(int i=(int)(s-1); i>=(int)(e); i--)
#define pb push_back
#define all(r) r.begin(),r.end()
#define rall(r) r.rbegin(),r.rend()
#define fi first
#define se second
  
typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
 
const int INF = 1e9;
const ll MOD = 1e9 + 7;
double EPS = 1e-8;

// #define DEBUG_MODE
#ifdef DEBUG_MODE
#define dump(x) cout << #x << " : " << x << endl
#define LINE cout << "line : " << __LINE__ << endl
#define dumpV(v) cout << #v << " : ["; for(auto& t : v) cout << t << ", "; cout<<"]" << endl
#define STOP assert(false)
#else
#define dump(x) ;
#define LINE     ;
#define dumpV(v);
#define STOP     ;
#endif
#define mp make_pair

namespace std{
  template<class S,class T>
  ostream &operator <<(ostream& out,const pair<S,T>& a){
    out<<'('<<a.fi<<", "<<a.se<<')';
    return out;
  }
}


int main(){
    int N, D, T;
    cin >> N >> D >> T;
    vl X(N);
    rep(i, N) cin >> X[i];
    sort(all(X));
    REP(i, 1, N) X[i] -= X[0];
    X[0] = 0;
    ll ans = 0LL;
    vector<int> used(N);
    rep(i, N) {
        if(used[i]) continue;
        vector<ll> cur;
        rep(j, N) {
            if(X[i] % D == X[j] % D) {
                used[j] = 1;
                cur.pb(X[j] / D);
            }
        } 
        dumpV(cur);

        ll L = cur[0] - T;
        ll R = cur[0] + T + 1;
        ans += R - L;
        REP(j, 1, cur.size()) {
            ll l = cur[j] - T;
            ll r = cur[j] + T + 1;
            ans += r - l;
            if(l < R) {
                ans -= R - l;
            }
            R = r;
        }
    }
    cout << ans << endl;
    return 0;
}