#include <bits/stdc++.h>
#define ll long long
#define INF 1000000005
#define MOD 1000000007
#define EPS 1e-10
#define rep(i,n) for(int i=0;i<(int)n;++i)
#define each(a,b) for(auto (a): (b))
#define all(v) (v).begin(),(v).end()
#define zip(v) sort(all(v)),v.erase(unique(all(v)),v.end())
#define fi first
#define se second
#define pb push_back
#define show(x) cout<<#x<<" = "<<(x)<<endl
#define spair(p) cout<<#p<<": "<<p.fi<<" "<<p.se<<endl
#define svec(v) cout<<#v<<":";rep(kbrni,v.size())cout<<" "<<v[kbrni];cout<<endl
#define sset(s) cout<<#s<<":";each(kbrni,s)cout<<" "<<kbrni;cout<<endl
#define smap(m) cout<<#m<<":";each(kbrni,m)cout<<" {"<<kbrni.first<<":"<<kbrni.second<<"}";cout<<endl

using namespace std;

typedef pair<int,int>P;

const int MAX_N = 101;

vector<ll> pos[MAX_N];
map<int,int> mp;

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    ll n,d,t;
    cin >> n >> d >> t;
    vector<int> vec(n);
    int id = 0;
    rep(i,n){
        ll a;
        cin >> a;
        if(mp.find((a+1000000001*d)%d) == mp.end()){
            pos[id].pb((a+1000000001*d)/d-1000000001);
            mp[(a+1000000001*d)%d] = id++;
        }else{
            pos[mp[(a+1000000001*d)%d]].pb((a+1000000001*d)/d-1000000001);
        }
    }
    ll ans = 0;
    rep(i,id){
        sort(all(pos[i]));
        rep(j,pos[i].size()){
            ans += 2*t+1;
            if(j != 0){
                ans -= max(0LL,(pos[i][j-1]+t) - (pos[i][j]-t) + 1);
            }
        }
    }
    cout << ans << endl;
    return 0;
}