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

int main() {

	ios_base::sync_with_stdio(0);
	cin.tie(0);

	int n, k, m, c; cin >> n >> k >> m >> c;
	vector<vector<bool>> a(n, vector<bool>(k, false));
	int ans = 0;
	for (int i = 0; i < c; i++) {
        int x; cin >> x;
        x--;
        int last = x + m;
        int melyik = -1;
        for (int j = 0; j < n; j++) {
            if (!a[j][x] && !a[j][last]) melyik = j;
        }
        if (melyik == -1) continue;
        ans++;
        for (int j = x; j < last; j++) {
            a[melyik][j] = true;
        }
	}
	cout << ans;

	return 0;
}