// Source: https://usaco.guide/general/io

#include <bits/stdc++.h>
#include <queue>
using namespace std;

int main() {
	int n, k, m, c;
	cin >> n >> k >> m >> c;
	priority_queue<int> end;
	int db = 0;
	for (int i = 0; i < c; i++) {
		int ig;
		cin >> ig;
		while (end.size() > 0 && end.top() >= -ig) end.pop();
		if (end.size() < n) {
			db++;
			end.push(-ig - m);
		}
	}

	cout << db;
}