#include <bits/stdc++.h>
#define For(i, a, b) for(int (i)=(int)(a); (i)<(int)(b); ++(i))
#define rFor(i, a, b) for(int (i)=(int)(a)-1; (i)>=(int)(b); --(i))
#define rep(i, n) For((i), 0, (n))
#define rrep(i, n) rFor((i), (n), 0)
#define fi first
#define se second
using namespace std;
typedef long long lint;
typedef unsigned long long ulint;
typedef pair<int, int> pii;
typedef pair<lint, lint> pll;
template<class T> bool chmax(T &a, const T &b){if(a<b){a=b; return true;} return false;}
template<class T> bool chmin(T &a, const T &b){if(a>b){a=b; return true;} return false;}
template<class T> T div_floor(T a, T b){
    if(b < 0) a *= -1, b *= -1;
    return a>=0 ? a/b : (a+1)/b-1;
}
template<class T> T div_ceil(T a, T b){
    if(b < 0) a *= -1, b *= -1;
    return a>0 ? (a-1)/b+1 : a/b;
}

constexpr lint mod = 1e9+7;
constexpr lint INF = mod * mod;
constexpr int MAX = 1000010;

int main(){
    int n; lint D, T;
    scanf("%d%lld%lld", &n, &D, &T);
    lint x[n];
    rep(i, n) scanf("%lld", &x[i]);
    map<lint, vector<lint>> mp;
    rep(i, n){
        mp[(x[i]%D+D)%D].push_back(x[i]);
    }
    lint ans = 0;
    for(auto [d, v]: mp){
        ans += T*2 + 1;
        sort(v.begin(), v.end());
        rep(i, v.size()-1){
            if(v[i]+T*D < v[i+1]-T*D) ans += T*2 + 1;
            else ans += (v[i+1]-v[i]) / D;
        }
    }
    printf("%lld\n", ans);
}