#include<iostream>
#include<map>
#include<vector>
#include<algorithm>
using namespace std;
int N;
long D,T;
main()
{
	cin>>N>>D>>T;
	map<long,vector<long> >M;
	for(int i=0;i<N;i++)
	{
		long X;cin>>X;
		M[(X%D+D)%D].push_back(X);
	}
	long ans=0;
	for(map<long,vector<long> >::iterator it=M.begin();it!=M.end();it++)
	{
		vector<long>tmp=it->second;
		sort(tmp.begin(),tmp.end());
		long pre=-2e18;
		for(long x:tmp)
		{
			long L=x-D*T,R=x+D*T;
			if(pre>=L)
			{
				ans-=(pre-L+D)/T;
			}
			ans+=2*T+1;
			pre=R;
		}
	}
	cout<<ans<<endl;
}