#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<int> vint;
typedef pair<int,int> pint;
typedef vector<pint> vpint;
#define rep(i,n) for(int i=0;i<(n);i++)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
#define each(it,v) for(__typeof((v).begin()) it=(v).begin();it!=(v).end();it++)
#define all(v) (v).begin(),(v).end()
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define chmax(a, b) a = (((a)<(b)) ? (b) : (a))
#define chmin(a, b) a = (((a)>(b)) ? (b) : (a))
const int MOD = 1e9 + 7;
const int INF = 1e9;
const ll INFF = 1e18;

int n;
ll d, t;
map<int, vector<pair<ll, ll>> > ran;
int main(void){
	cin >> n >> d >> t;
	vector<ll> x;
	rep(i, n){
		ll t; cin >> t;
		t += (ll)INF; //modとるときに負にならないように
		x.pb(t);
	}

	sort(all(x));
	for(auto u : x){ //modをとって範囲をいれていく.
		ran[u % d].pb(mp(u - d * t, u + d * t));
	}

	ll ans = 0;
	for(auto v : ran){
		ll left = -INFF, right = -INFF;		
		for(auto u : v.second){
			ll nleft = u.fi, nright = u.se;
			if(nleft > right){ //連続区間でないとき
				if(left != -INFF) ans += (right - left) / d + 1;
				left = nleft;
				right = nright;
			}else{
				right = nright;
			}
		}
		if(left != -INFF) ans += (right - left) / d + 1;
	}
	printf("%lld\n", ans);
	return 0;
}