#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

typedef vector<pair<long long, long long>> Intervals;
Intervals mergeIntervals(Intervals a){
    Intervals res;
    sort(all(a));
    for(const auto & b: a){
        if(res.size() == 0 || res.back().second < b.first)
            res.push_back(b);
        else
            res.back().second = max(res.back().second, b.second);
    }
    return res;
}

int main(){
    int N, D, T;
    cin >> N >> D >> T;
    map<int, Intervals> ma;
    rep(i, N){
        int X; scanf("%d", &X);
        ll l = X - (ll)D*T, r = X + (ll)D*T + 1;
        int mod = ((X%D) + D) % D;
        if(!ma.count(mod)){
            ma[mod] = Intervals{mp(l,r)};
        } else{
            Intervals lrs = ma[mod];
            lrs.push_back(mp(l, r));
            ma[mod] = mergeIntervals(lrs);
        }
    }
    ll ans = 0;
    each(p, ma){
        each(lr, p.second){
            ll l = lr.first, r = lr.second;
            ans += (r - l) / D + 1;
        }
    }
    cout << ans << endl;
}