#include<bits/stdc++.h>
using namespace std;
#define REP(x,y)for(ll x=0;x<ll(y);++x)
#define rep(x,y,z)for(ll x=ll(y);x<ll(z);++x)
#define PER(x,y)for(ll x=ll(y)-1;x>=0;--x)
#define per(x,y,z)for(ll x=ll(z)-1;x>=ll(y);--x)
#define all(v)begin(v),end(v)
#define rall(v)rbegin(v),rend(v)
#define pb emplace_back
#define fi first
#define se second
#define lb(v,k)ll(lower_bound(all(v),k)-begin(v))
#define ub(v,k)ll(upper_bound(all(v),k)-begin(v))
#define uniq(v)sort(all(v)),v.erase(unique(all(v)),v.end())
#define sz(x)ll(x.size())
#define out(x)cout<<(x)<<'\n'
#define sor(v)sort(all(v))
using ll=long long;
using P=pair<ll,ll>;
using PP=tuple<ll,ll,ll>;
using PPP=tuple<ll,ll,ll,ll>;
using vi=vector<ll>;
using vvi=vector<vi>;
using vb=vector<bool>;
using vvb=vector<vb>;
using vp=vector<P>;
using vvp=vector<vp>;
struct $_${$_$(){ios::sync_with_stdio(false);cin.tie(nullptr);}}$_$_$;
template<class T>inline bool chmin(T&A,T B){if(A>B){A=B;return true;}return false;}
template<class T>inline bool chmax(T&A,T B){if(A<B){A=B;return true;}return false;}
int main()
{
	ll N,D,T;
	cin>>N>>D>>T;
	vi X(N);
	REP(i,N)cin>>X[i];
	map<ll,vi>mp;
	REP(i,N)mp[(X[i]+ll(1e9))%D].pb((X[i]+ll(1e9))/D);
	ll ans=0;
	for(auto[_,e]:mp)
	{
		sort(all(e));
		int n=sz(e);
		for(int i=0,j=0;i<n;i=j)
		{
			while(j+1<n&&e[j+1]-e[j]-1<=T*2)++j;
			ans+=(e[j]+T)-(e[i]-T)+1;
			++j;
		}
	}
	out(ans);
}