#include<bits/stdc++.h>
using namespace std;

#define int long long

typedef long long ll;
typedef pair<int,int>pint;
typedef vector<int>vint;
typedef vector<pint>vpint;
#define pb push_back
#define mp make_pair
#define fi first
#define se second
#define ln <<endl
#define all(v) (v).begin(),(v).end()
#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++)
template<class T,class U>void chmin(T &t,U f){if(t>f)t=f;}
template<class T,class U>void chmax(T &t,U f){if(t<f)t=f;}

int N,D,T;
int X[100];
int l[100],r[100];
signed main(){
    cin>>N>>D>>T;
    rep(i,N)cin>>X[i];

    map<int,vint>M;
    rep(i,N)M[(X[i]+D*1000000000)%D].pb(X[i]);

    int ans=0;
    for(auto it:M){
        vint &v=it.se;
        sort(all(v));
        rep(i,v.size()){
            v[i]-=it.fi;
            v[i]/=D;
            l[i]=v[i]-T;
            r[i]=v[i]+T;
        }

        int cur=0;
        while(cur<v.size()){
            int next=cur+1;
            while(next<v.size()&&r[next-1]>=l[next])next++;
            ans+=r[next-1]-l[cur]+1;
            cur=next;
        }
    }

    cout<<ans<<endl;
    return 0;
}