#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, m, n) for (int i = m; i < n; ++i)
#define FORR(i, m, n) for (int i = m; i >= n; --i)
#define ALL(v) (v).begin(),(v).end()
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
const ll INF=1LL<<60;
const int inf=(1<<30)-1;
const int mod=1e9+7;
int dx[8]={1,0,-1,0,-1,-1,1,1};
int dy[8]={0,1,0,-1,-1,1,-1,1};
int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll n,d,t;cin >> n >> d >> t;
    vector<ll> x(n);
    vector<ll> r;
    map<ll,ll> mp;
    REP(i,n){
        cin >> x[i];
        ll rem=(inf*d+x[i])%d;
        if(!mp.count(rem)){
            r.push_back(rem);
            mp[rem]=r.size()-1;
        }
    }
    int rs=r.size();
    vector<vector<pair<ll,ll>>> p(rs);
    REP(i,n){
        ll rem=(inf*d+x[i])%d;
        p[mp[rem]].push_back({x[i]/d-t,x[i]/d+t});
    }
    ll ans=0;
    REP(i,rs){
        sort(ALL(p[i]));
        ll mi=-INF,ma=-INF-1;
        for(auto x:p[i]){
            if(x.first>ma){
                ans+=ma-mi+1;
                mi=x.first;
            }
            chmax(ma,x.second);
        }
        ans+=ma-mi+1;
    }
    cout << ans << endl;
}