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

template<typename type>
void vector_sort(vector<type>& v,function<int(type)> fn=[](int a){return a;},int decided=0){
    int range=v.size()-decided;
    if(range==0){
        return;
    }
    int parent=(v.size()-decided-1)/2;
    int child=parent*2+1;
    int parent_depth=1;
    while(pow(2,parent_depth)-1<range){
        parent_depth++;
    }
    parent_depth-=2;
    type temp;
    while(parent_depth>=0){
        for(int i=pow(2,parent_depth)-1;i<pow(2,parent_depth+1)-1;i++){
            if(i*2+1<range && v[i]<v[i*2+1]){
                temp=v[i];
                v[i]=v[i*2+1];
                v[i*2+1]=temp;
            }
            if(i*2+2<range && v[i]<v[i*2+2]){
                temp=v[i];
                v[i]=v[i*2+2];
                v[i*2+2]=temp;
            }
        }
        parent_depth--;
    }
    temp=v[0];
    v[0]=v[range-1];
    v[range-1]=temp;
    vector_sort(v,fn,decided+1);
}

int main(){
    int N,D,T;
    cin>>N>>D>>T;
    vector<int> X(N);
    for(int i=0;i<N;i++){
        cin>>X[i];
    }
    vector_sort(X);
    vector<vector<int>> processed(D,vector<int>(0));
    for(int i=0;i<N;i++){
        processed[X[i]%D].push_back(X[i]/D);
    }
    long long ans=0;
    for(int i=0;i<D;i++){
        if(processed[i].size()>0){
            ans+=2*T+1;
        }
        for(int j=1;j<processed[i].size();j++){
            if(processed[i][j]-processed[i][j-1]-1>2*T){
                ans+=2*T+1;
            }else{
                ans+=processed[i][j]-processed[i][j-1];
            }
        }
    }
    cout<<ans<<endl;
}