#include <cstdio> #include <iostream> #include <string> #include <sstream> #include <stack> #include <algorithm> #include <cmath> #include <queue> #include <map> #include <set> #include <cstdlib> #include <bitset> #include <tuple> #include <assert.h> #include <deque> #include <bitset> #include <iomanip> #include <limits> #include <chrono> #include <random> #include <array> #include <unordered_map> #include <functional> #include <complex> #include <numeric> template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } //constexpr long long MAX = 5100000; constexpr long long INF = 1LL << 60; constexpr int inf = 1000000007; //constexpr long long mod = 1000000007LL; //constexpr long long mod = 998244353LL; const long double PI = acos((long double)(-1)); using namespace std; typedef unsigned long long ull; typedef long long ll; typedef long double ld; int main() { /* cin.tie(nullptr); ios::sync_with_stdio(false); */ int n, D, T; scanf("%d %d %d", &n, &D, &T); vector<int> x(n); for (int i = 0; i < n; i++) scanf("%d", &x[i]); map<int, vector<int>> mp; for (int i = 0; i < n; i++) mp[(x[i] % D + D) % D].emplace_back(x[i]); ll res = 0; for (auto& p : mp) { auto& v = p.second; sort(v.begin(), v.end()); for (int i = 0; i + 1 < v.size(); i++) { int t = (v[i + 1] - v[i]) / D; res += min(t, T * 2 + 1); } res += T + T + 1; } cout << res << endl; return 0; }