#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main(){
    long long N, M, V, P; cin >> N >> M >> V >> P;
    vector<long long> A(N);
    for(auto& t : A) cin >> t;
    sort(A.begin(), A.end());
    int L = -1, R = N-1;
    while(R-L > 1){
        int mid = (L+R)/2;
        long long thr = A[mid] + M;
        int gr = 0;
        long long add = M;
        for(int j=N-1;j>=0;j--){
            if(j == mid) continue;
            if(A[j] > thr){
                gr++;
                add += M;
            } else {
                if(gr+1 < P && A[j]+M > thr){
                    gr++;
                    add += M;
                } else {
                    add += min(M, thr-A[j]);
                }
            }
        }
        if(gr < P && add >= M*V) R = mid;
        else L = mid;
    }
    cout << N-R << endl;
}
//Author:xht37
#include <bits/stdc++.h>

#define ui unsigned int
#define ll long long
#define ul unsigned ll
#define ld long double

#define pi pair <int, int>
#define fi first
#define se second
#define mp make_pair

#define ls (p << 1)
#define rs (ls | 1)
#define md ((t[p].l + t[p].r) >> 1)

#define vi vector <int>
#define pb push_back
#define pq priority_queue

#define dbg(x) cerr << #x" = " << x << endl
#define debug(...) fprintf(stderr, __VA_ARGS__)

#define fl(x) freopen(x".in", "r", stdin), freopen(x".out", "w", stdout)

using namespace std;

namespace io {
	const int SI = 1 << 21 | 1;
	char IB[SI], *IS, *IT, OB[SI], *OS = OB, *OT = OS + SI - 1, c, ch[100];
	int f, t;
	#define gc() (IS == IT ? (IT = (IS = IB) + fread(IB, 1, SI, stdin), IS == IT ? EOF : *IS++) : *IS++)
	inline void flush() {
		fwrite(OB, 1, OS - OB, stdout), OS = OB;
	}
	inline void pc(char x) {
		*OS++ = x;
		if (OS == OT) flush();
	}

	template <class I>
	inline void rd(I &x) {
		for (f = 1, c = gc(); c < '0' || c > '9'; c = gc()) if (c == '-') f = -1;
		for (x = 0; c >= '0' && c <= '9'; x = (x << 3) + (x << 1) + (c & 15), c = gc());
		x *= f;
	}
	template <class I>
	inline void rd(I &x, I &y) {
		rd(x), rd(y);
	}
	template <class I>
	inline void rd(I &x, I &y, I &z) {
		rd(x), rd(y), rd(z);
	}
	template <class I>
	inline void rda(I *a, int n) {
		for (int i = 1; i <= n; i++) rd(a[i]);
	}
	inline void rdc(char &c) {
		for (c = gc(); c < 33 || c > 126; c = gc());
	}
	inline void rds(char *s, int &n) {
		for (c = gc(); c < 33 || c > 126; c = gc());
		for (n = 0; c >= 33 && c <= 126; s[++n] = c, c = gc());
		s[n+1] = '\0';
	}
	inline void rds(string &s) {
		for (c = gc(); c < 33 || c > 126; c = gc());
		for (s.clear(); c >= 33 && c <= 126; s.pb(c), c = gc());
	}

	template <class I>
	inline void print(I x, char k = '\n') {
		if (!x) pc('0');
		if (x < 0) pc('-'), x = -x;
		while (x) ch[++t] = x % 10 + '0', x /= 10;
		while (t) pc(ch[t--]);
		pc(k);
	}
	template <class I>
	inline void print(I x, I y) {
		print(x, ' '), print(y);
	}
	template <class I>
	inline void print(I x, I y, I z) {
		print(x, ' '), print(y, ' '), print(z);
	}
	template <class I>
	inline void printa(I *a, int n) {
		for (int i = 1; i <= n; i++) print(a[i], " \n"[i==n]);
	}
	inline void printc(char c) {
		pc(c);
	}
	inline void prints(char *s, int n) {
		for (int i = 1; i <= n; i++) pc(s[i]);
		pc('\n');
	}
	inline void prints(string s) {
		int n = s.length();
		while (t < n) pc(s[t++]);
		pc('\n'), t = 0;
	}
	struct Flush {
		~Flush() {
			flush();
		}
	} flusher;
}
using io::rd;
using io::rda;
using io::rdc;
using io::rds;
using io::print;
using io::printa;
using io::printc;
using io::prints;

namespace shai {
	const int n = 1e6 + 7;
	int p[n], v[n], phi[n], miu[n];

	inline void init(int n) {
		v[1] = phi[1] = miu[1] = 1;
		for (int i = 2; i <= n; i++) {
			if (!v[i]) p[++p[0]] = v[i] = i, phi[i] = i - 1, miu[i] = -1;
			for (int j = 1; j <= p[0] && i * p[j] <= n && p[j] <= v[i]; j++)
				v[i*p[j]] = p[j],
				phi[i*p[j]] = phi[i] * (p[j] - 1 + (p[j] == v[i])),
				miu[i*p[j]] = p[j] == v[i] ? 0 : -miu[i];
		}
	}
}
using shai::p;

const int N = 507;
int n, a[N], b[N];

int main() {
	shai::init(1e4);
	rd(n);
	for (int i = 1; i <= n; i++) a[i] = p[i&1?i/2+1:n*2-i/2+1];
	for (int i = 1; i <= n; i++) b[i] = p[(i&1?n-i/2:n+i/2)+(n&1)];
	a[0] = a[n+1] = b[0] = b[n+1] = 1;
	for (int i = 1; i <= n; i++)
		for (int j = 1; j <= n; j++)
			print((i ^ j) & 1 ? 1ll * a[(i+j)/2] * a[(i+j)/2+1] * b[(n+i-j+(n&1))/2] * b[(n+i-j+(n&1))/2+1] + 1 : 1ll * a[(i+j)/2] * b[(n+i-j+(n&1))/2], " \n"[j==n]);
	return 0;
}