#include<iostream>
#include<sstream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<string>
#include<vector>
#include<cmath>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<numeric>
#include<functional>
#include<complex>

using namespace std;
#define BET(a,b,c) ((a)<=(b)&&(b)<(c))
#define FOR(i,n) for(int i=0,i##_end=(int(n));i<i##_end;i++)
#define SZ(x) (int)(x.size())
#define ALL(x) (x).begin(),(x).end()
#define MP make_pair
#define FOR_EACH(it,v) for(__typeof(v.begin()) it=v.begin(),it_end=v.end() ; it != it_end ; it++)
typedef vector<int> VI;
typedef vector<VI> VVI;

int main()
{
    int N,D,T;
    cin>>N>>D>>T;
    map<long long,vector<long long> > group;
    FOR(i,N){
        long long X;
        cin>>X;
        X += 1000000000;
        group[X % D].push_back(X / D);
    }
    long long ans = 0 ;
    for(auto p : group){
        vector<long long> v(p.second);
        sort(ALL(v));
        long long range = v[SZ(v)-1] - v[0] + 2LL * T + 1;
        FOR(i,SZ(v) - 1) {
            range -= max(v[i + 1] - v[i] - 1 - 2LL * T, 0LL);
        }
        ans += range;
    }
    cout<<ans<<endl;
    return 0;
}