#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cmath>
#include <complex>
#include <deque>
#include <forward_list>
#include <fstream>
#include <functional>
#include <iomanip>
#include <ios>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <memory>
#include <numeric>
#include <optional>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <tuple>
#include <type_traits>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>
using namespace std;
using lint = long long;
using pint = pair<int, int>;
using plint = pair<lint, lint>;
struct fast_ios { fast_ios(){ cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(20); }; } fast_ios_;
#define ALL(x) (x).begin(), (x).end()
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
template <typename T> bool chmax(T &m, const T q) { return m < q ? (m = q, true) : false; }
template <typename T> bool chmin(T &m, const T q) { return m > q ? (m = q, true) : false; }
const std::vector<std::pair<int, int>> grid_dxs{{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
int floor_lg(long long x) { return x <= 0 ? -1 : 63 - __builtin_clzll(x); }
template <class T1, class T2> T1 floor_div(T1 num, T2 den) { return (num > 0 ? num / den : -((-num + den - 1) / den)); }
template <class T1, class T2> std::pair<T1, T2> operator+(const std::pair<T1, T2> &l, const std::pair<T1, T2> &r) { return std::make_pair(l.first + r.first, l.second + r.second); }
template <class T1, class T2> std::pair<T1, T2> operator-(const std::pair<T1, T2> &l, const std::pair<T1, T2> &r) { return std::make_pair(l.first - r.first, l.second - r.second); }
template <class T> std::vector<T> sort_unique(std::vector<T> vec) { sort(vec.begin(), vec.end()), vec.erase(unique(vec.begin(), vec.end()), vec.end()); return vec; }
template <class T> int arglb(const std::vector<T> &v, const T &x) { return std::distance(v.begin(), std::lower_bound(v.begin(), v.end(), x)); }
template <class T> int argub(const std::vector<T> &v, const T &x) { return std::distance(v.begin(), std::upper_bound(v.begin(), v.end(), x)); }
template <class IStream, class T> IStream &operator>>(IStream &is, std::vector<T> &vec) { for (auto &v : vec) is >> v; return is; }

template <class OStream, class T> OStream &operator<<(OStream &os, const std::vector<T> &vec);
template <class OStream, class T, size_t sz> OStream &operator<<(OStream &os, const std::array<T, sz> &arr);
template <class OStream, class T, class TH> OStream &operator<<(OStream &os, const std::unordered_set<T, TH> &vec);
template <class OStream, class T, class U> OStream &operator<<(OStream &os, const pair<T, U> &pa);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::deque<T> &vec);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::set<T> &vec);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::multiset<T> &vec);
template <class OStream, class T> OStream &operator<<(OStream &os, const std::unordered_multiset<T> &vec);
template <class OStream, class T, class U> OStream &operator<<(OStream &os, const std::pair<T, U> &pa);
template <class OStream, class TK, class TV> OStream &operator<<(OStream &os, const std::map<TK, TV> &mp);
template <class OStream, class TK, class TV, class TH> OStream &operator<<(OStream &os, const std::unordered_map<TK, TV, TH> &mp);
template <class OStream, class... T> OStream &operator<<(OStream &os, const std::tuple<T...> &tpl);

template <class OStream, class T> OStream &operator<<(OStream &os, const std::vector<T> &vec) { os << '['; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <class OStream, class T, size_t sz> OStream &operator<<(OStream &os, const std::array<T, sz> &arr) { os << '['; for (auto v : arr) os << v << ','; os << ']'; return os; }
template <class... T> std::istream &operator>>(std::istream &is, std::tuple<T...> &tpl) { std::apply([&is](auto &&... args) { ((is >> args), ...);}, tpl); return is; }
template <class OStream, class... T> OStream &operator<<(OStream &os, const std::tuple<T...> &tpl) { os << '('; std::apply([&os](auto &&... args) { ((os << args << ','), ...);}, tpl); return os << ')'; }
template <class OStream, class T, class TH> OStream &operator<<(OStream &os, const std::unordered_set<T, TH> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::deque<T> &vec) { os << "deq["; for (auto v : vec) os << v << ','; os << ']'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::set<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T> OStream &operator<<(OStream &os, const std::unordered_multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }
template <class OStream, class T, class U> OStream &operator<<(OStream &os, const std::pair<T, U> &pa) { return os << '(' << pa.first << ',' << pa.second << ')'; }
template <class OStream, class TK, class TV> OStream &operator<<(OStream &os, const std::map<TK, TV> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
template <class OStream, class TK, class TV, class TH> OStream &operator<<(OStream &os, const std::unordered_map<TK, TV, TH> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }
#ifdef HITONANODE_LOCAL
const string COLOR_RESET = "\033[0m", BRIGHT_GREEN = "\033[1;32m", BRIGHT_RED = "\033[1;31m", BRIGHT_CYAN = "\033[1;36m", NORMAL_CROSSED = "\033[0;9;37m", RED_BACKGROUND = "\033[1;41m", NORMAL_FAINT = "\033[0;2m";
#define dbg(x) std::cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET << std::endl
#define dbgif(cond, x) ((cond) ? std::cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET << std::endl : std::cerr)
#else
#define dbg(x) ((void)0)
#define dbgif(cond, x) ((void)0)
#endif


int main() {
    int N, K;
    lint L_, U_;
    cin >> N >> K >> L_ >> U_;
    const lint W = U_ - L_;

    vector<lint> A(N);
    cin >> A;
    // REP(i, N) A.at(i) += K;
    sort(ALL(A));
    dbg(make_tuple(K, W, A));

    auto eval = [&](lint lo) -> __int128 {
        const lint hi = lo + W;
        __int128 ret = 0;
        for (const lint &v : A) {
            if (v < lo) {
                ret += (lo - v + K - 1) / K;
            } else if (v > hi) {
                ret += (v - hi + K - 1) / K;
            }
            assert(ret >= 0);
        }
        return ret;
    };

    lint lo = 0, hi = 1LL << 40;
    dbg(hi);

    __int128 ans = __int128(1) << 120;
    while (hi - lo > 2) {
        const auto c1 = (lo * 2 + hi) / 3, c2 = (lo + hi * 2) / 3;
        auto e1 = eval(c1);
        auto e2 = eval(c2);
        chmin(ans, e1);
        chmin(ans, e2);
        if (e1 < e2) {
            hi = c2;
        } else {
            lo = c1;
        }
    }
    for (lint i = lo; i <= hi; ++i) {
        chmin(ans, eval(i));
    }
    dbg(make_tuple(lo, hi));

    cout << (lint)ans - 1 << '\n';

    // vector<vector<lint>> mod2i(K);

    // multiset<lint> lo, hi;
    // lint losum = 0;
    // lint hisum = 0;

    // auto get_eval = [&]() -> lint {
    //     if (hi.size()) {
    //         const lint c = *hi.begin();
    //         return (c * (lint)lo.size() - losum) + hisum - c * (lint)hi.size();
    //     } else {
    //         return 0;
    //     }
    // };

    // auto balance = [&]() {
    //     while (hi.size() > lo.size() + 1) {
    //         auto it = hi.begin();
    //         lo.insert(*it);
    //         losum += *it;
    //         hisum -= *it;
    //         hi.erase(it);
    //     }
    //     while (lo.size() > hi.size() + 1) {
    //         auto it = lo.end();
    //         --it;
    //         hi.insert(*it);
    //         hisum += *it;
    //         losum -= *it;
    //         lo.erase(it);
    //     }

    //     while (lo.size() and hi.size() and *lo.rbegin() > *hi.begin()) {
    //         auto itlo = lo.end();
    //         --itlo;
    //         auto ithi = hi.begin();
    //         losum += *ithi;
    //         hisum -= *ithi;
    //         hisum += *itlo;
    //         losum -= *itlo;
    //         lo.insert(*ithi);
    //         hi.insert(*itlo);
    //         lo.erase(itlo);
    //         hi.erase(ithi);
    //     }
    // };

    // auto add = [&](lint x) {
    //     if (lo.size() < hi.size()) {
    //         lo.insert(x);
    //         losum += x;
    //     } else {
    //         hi.insert(x);
    //         hisum += x;
    //     }
    //     balance();
    // };

    // auto remove = [&](lint x) {
    //     if (lo.count(x)) {
    //         lo.erase(lo.find(x));
    //         losum -= x;
    //     } else {
    //         assert(hi.count(x));
    //         hi.erase(hi.find(x));
    //         hisum -= x;
    //     }
    //     balance();
    // };

    // lint ret = 1LL << 60;

    // REP(i, N) {
    //     const lint a = A.at(i);
    //     mod2i.at(a % K).emplace_back(a / K);
    //     dbg(a / K);
    //     add(a / K);
    // }
    // chmin(ret, get_eval());
    // dbg(ret);
    // dbg(lo);
    // dbg(hi);
    // dbg(losum);
    // dbg(hisum);

    // REP(k, K) {
    //     for (auto a : mod2i.at(k)) {
    //         remove(a);
    //         add(a - 1);
    //     }
    //     dbgif(K <= 100, make_tuple(lo, hi, losum, hisum, get_eval()));
    //     chmin(ret, get_eval());
    // }

    // cout << ret << '\n';
}