#include <iostream>

using namespace std;

int main()
{
    int n, k, m, c;

    cin >> n >> k >> m >> c;

    int foglalt[10] = {0};
    int db = 0;

    for (int i = 0; i < c; i ++) {
        int kezdn;
        cin >> kezdn;
        for (int j = 0; j < n; j ++) {
            if (foglalt[j] < kezdn) {
                db ++;
                foglalt[j] = kezdn + m - 1;
                break;
            }
        }
    }

    cout << db;
    return 0;
}