#ifdef NACHIA
#define _GLIBCXX_DEBUG
#else
#define NDEBUG
#endif
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <queue>
#include <array>
#include <cmath>
#include <atcoder/modint>
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(i64 i=0; i<(i64)(n); i++)
#define repr(i,n) for(i64 i=(i64)(n)-1; i>=0; i--)
const i64 INF = 1001001001001001001;
const char* yn(bool x){ return x ? "Yes" : "No"; }
template<typename A> void chmin(A& l, const A& r){ if(r < l) l = r; }
template<typename A> void chmax(A& l, const A& r){ if(l < r) l = r; }
template<typename A> using nega_queue = std::priority_queue<A,std::vector<A>,std::greater<A>>;
using Modint = atcoder::static_modint<998244353>;

#include <iterator>
#include <functional>

template<class Elem> struct vec;

template<class Iter>
struct seq_view{
    using Ref = typename std::iterator_traits<Iter>::reference;
    using Elem = typename std::iterator_traits<Iter>::value_type;
    Iter a, b;
    Iter begin() const { return a; }
    Iter end() const { return b; }
    int size() const { return (int)(b-a); }
    seq_view(Iter first, Iter last) : a(first), b(last) {}
    seq_view sort() const { std::sort(a, b); return *this; }
    Ref& operator[](int x){ return *(a+x); }
    template<class F = std::less<Elem>, class ret = vec<int>> ret sorti(F f = F()) const {
        ret x(size()); for(int i=0; i<size(); i++) x[i] = i;
        x().sort([&](int l, int r){ return f(a[l],a[r]); });
        return x;
    }
    template<class ret = vec<Elem>> ret col() const { return ret(begin(), end()); }
    template<class F = std::equal_to<Elem>, class ret = vec<std::pair<Elem, int>>>
    ret rle(F eq = F()) const {
        auto x = ret();
        for(auto& a : (*this)){
            if(x.size() == 0 || !eq(x[x.size()-1].first, a)) x.emp(a, 1); else x[x.size()-1].second++;
        } return x;
    }
    template<class F> seq_view sort(F f) const { std::sort(a, b, f); return *this; }
    Iter uni() const { return std::unique(a, b); }
    Iter lb(const Elem& x) const { return std::lower_bound(a, b, x); }
    Iter ub(const Elem& x) const { return std::upper_bound(a, b, x); }
    int lbi(const Elem& x) const { return lb(x) - a; }
    int ubi(const Elem& x) const { return ub(x) - a; }
    seq_view bound(const Elem& l, const Elem& r) const { return { lb(l), lb(r) }; }
    template<class F> Iter lb(const Elem& x, F f) const { return std::lower_bound(a, b, x, f); }
    template<class F> Iter ub(const Elem& x, F f) const { return std::upper_bound(a, b, x, f); }
    template<class F> Iter when_true_to_false(F f) const {
        if(a == b) return a;
        return std::lower_bound(a, b, *a,
            [&](const Elem& x, const Elem&){ return f(x); });
    }
    seq_view same(Elem x) const { return { lb(x), ub(x) }; }
    template<class F> auto map(F f) const {
        vec<typename Iter::value_type> r;
        for(auto& x : *this) r.emp(f(x));
        return r;
    }
    Iter max() const { return std::max_element(a, b); }
    Iter min() const { return std::min_element(a, b); }
    template<class F = std::less<Elem>>
    Iter min(F f) const { return std::min_element(a, b, f); }
    seq_view rev() const { std::reverse(a, b); return *this; }
};

template<class Elem>
struct vec {
    using Base = typename std::vector<Elem>;
    using Iter = typename Base::iterator;
    using CIter = typename Base::const_iterator;
    using View = seq_view<Iter>;
    using CView = seq_view<CIter>;

    vec(){}
    explicit vec(int n, const Elem& value = Elem()) : a(0<n?n:0, value) {}
    template <class I2> vec(I2 first, I2 last) : a(first, last) {}
    vec(std::initializer_list<Elem> il) : a(std::move(il)) {}
    vec(Base b) : a(std::move(b)) {}
    operator Base() const { return a; }

    Iter begin(){ return a.begin(); }
    CIter begin() const { return a.begin(); }
    Iter end(){ return a.end(); }
    CIter end() const { return a.end(); }
    int size() const { return a.size(); }
    bool empty() const { return a.empty(); }
    Elem& back(){ return a.back(); }
    const Elem& back() const { return a.back(); }
    vec sortunied(){ vec x = *this; x().sort(); x.a.erase(x().uni(), x.end()); return x; }
    Iter operator()(int x){ return a.begin() + x; }
    CIter operator()(int x) const { return a.begin() + x; }
    View operator()(int l, int r){ return { (*this)(l), (*this)(r) }; }
    CView operator()(int l, int r) const { return { (*this)(l), (*this)(r) }; }
    View operator()(){ return (*this)(0,size()); }
    CView operator()() const { return (*this)(0,size()); }
    Elem& operator[](int x){ return a[x]; }
    const Elem& operator[](int x) const { return a[x]; }
    Base& operator*(){ return a; }
    const Base& operator*() const { return a; }
    vec& push(Elem args){
        a.push_back(std::move(args));
        return *this;
    }
    template<class... Args>
    vec& emp(Args &&... args){
        a.emplace_back(std::forward<Args>(args) ...);
        return *this;
    }
    template<class Range>
    vec& app(Range& x){ for(auto& v : a) emp(v); }
    Elem pop(){
        Elem x = std::move(a.back());
        a.pop_back(); return x;
    }
    bool operator==(const vec& r) const { return a == r.a; }
    bool operator!=(const vec& r) const { return a != r.a; }
    bool operator<(const vec& r) const { return a < r.a; }
    bool operator<=(const vec& r) const { return a <= r.a; }
    bool operator>(const vec& r) const { return a > r.a; }
    bool operator>=(const vec& r) const { return a >= r.a; }
    vec<vec<Elem>> pile(int n) const { return vec<vec<Elem>>(n, *this); }
    template<class F> vec& filter(F f){
        int p = 0;
        for(int q=0; q<size(); q++) if(f(a[q])) std::swap(a[p++],a[q]);
        a.resize(p); return *this;
    }
private: Base a;
};

template<class IStr, class U, class T>
IStr& operator>>(IStr& is, vec<std::pair<U,T>>& v){ for(auto& x:v){ is >> x.first >> x.second; } return is; }
template<class IStr, class T>
IStr& operator>>(IStr& is, vec<T>& v){ for(auto& x:v){ is >> x; } return is; }
template<class OStr, class T>
OStr& operator<<(OStr& os, const vec<T>& v){
    for(int i=0; i<v.size(); i++){
        if(i){ os << ' '; } os << v[i];
    } return os;
}
template<class OStr, class U, class T>
OStr& operator<<(OStr& os, const vec<std::pair<U,T>>& v){
    for(int i=0; i<v.size(); i++){
        if(i){ os << ' '; } os << '(' << v[i].first << ',' << v[i].second << ')';
    } return os;
}
using namespace std;


struct SlopeTrick {
    using Value = long long;
    std::priority_queue<Value, std::vector<Value>, std::less<Value>> lque;
    std::priority_queue<Value, std::vector<Value>, std::greater<Value>> rque;
    std::priority_queue<Value, std::vector<Value>, std::less<Value>> lremque;
    std::priority_queue<Value, std::vector<Value>, std::greater<Value>> rremque;
    Value m_min;
    Value m_max;
    Value m_zero;
    Value m_minVal;
    Value argMinL() const {
        return lque.empty() ? m_min : lque.top();
    }
    Value argMinR() const {
        return rque.empty() ? m_max : rque.top();
    }
    Value minValue() const { return m_minVal; }
    SlopeTrick(Value MIN, Value MAX, Value ZERO = Value(0))
        : m_min(MIN), m_max(MAX), m_zero(ZERO), m_minVal(ZERO) {}
    void leftUp(Value pos){
        if(!rque.empty() && rque.top() < pos){
            m_minVal += pos - rque.top();
            lque.push(rPop()); rque.push(pos);
        } else { lque.push(pos); }
    }
    void rightUp(Value pos){
        if(!lque.empty() && pos < lque.top()){
            m_minVal += lque.top() - pos;
            rque.push(lPop()); lque.push(pos);
        } else { rque.push(pos); }
    }
    void leftRemove(Value pos){
        Value x = lque.top();
        if(x == pos){ lPop(); return; }
        if(pos < x){ lremque.push(pos); return; }
        m_minVal -= pos - x;
        rque.push(lPop());
        rremque.push(pos);
    }
    void rightRemove(Value pos){
        Value x = rque.top();
        if(x == pos){ rPop(); return; }
        if(x < pos){ rremque.push(pos); return; }
        m_minVal -= x - pos;
        lque.push(rPop());
        lremque.push(pos);
    }
private:
    Value lPop(){
        Value buf = lque.top(); lque.pop();
        while(!lremque.empty() && lque.top() == lremque.top()){
            lque.pop(); lremque.pop();
        }
        return buf;
    }
    Value rPop(){
        Value buf = rque.top(); rque.pop();
        while(!rremque.empty() && rque.top() == rremque.top()){
            rque.pop(); rremque.pop();
        }
        return buf;
    }
};

template<typename Int>
Int FloorDiv(Int a, Int b){
    if(b < Int(0)){ a = -a; b = -b; }
    if(a >= Int(0) || a % b == Int(0)) return a / b;
    return a / b - Int(1);
}

template<typename Int>
Int CeilDiv(Int a, Int b){
    if(b < Int(0)){ a = -a; b = -b; }
    if(a < Int(0) || a % b == Int(0)) return a / b;
    return a / b + Int(1);
}



void testcase(){
    i64 N, K, L, R; cin >> N >> K >> L >> R;
    vec<i64> A(N); cin >> A;
    SlopeTrick slope(-INF, INF);
    vec<pair<i64, pair<i64, i64>>> query;
    rep(i,N){
        i64 ld = CeilDiv(L - A[i], K);
        i64 lm = ld * K - (L - A[i]);
        slope.rightUp(-ld);
        query.push({ lm+1, { 1, -ld-1 } });
        query.push({ lm+1, { 3, -ld } });
    }
    rep(i,N){
        i64 ld = CeilDiv(A[i] - R, K);
        i64 lm = ld * K - (A[i] - R);
        slope.leftUp(ld);
        query.push({ K-lm, { 2, ld-1 } });
        query.push({ K-lm, { 4, ld } });
    }
    query().sort();
    i64 ans = slope.minValue();
    for(auto [t, q] : query){
        auto [c, x] = q;
        if(c == 1) slope.rightUp(x);
        if(c == 2) slope.leftUp(x);
        if(c == 3) slope.rightRemove(x);
        if(c == 4) slope.leftRemove(x);
        chmin(ans, slope.minValue());
    }
    cout << ans << endl;
}

int main(){
    ios::sync_with_stdio(false); cin.tie(nullptr);
    #ifdef NACHIA
    int T; cin >> T; for(int t=0; t<T; T!=++t?(cout<<'\n'),0:0)
    #endif
    testcase();
    return 0;
}