#include <iostream>

using namespace std;

int main()
{
    int n, k, m, c, A[10] = {0}, x, ans = 0;
    cin >> n >> k >> m >> c;
    for(int i = 0; i < c; i++)
    {
        cin >> x;
        for(int j = 0; j < n; j++)
        {
            if(A[j] < x)
            {
                ans++;
                A[j] = x + m - 1;
                break;
            }
        }
    }
    cout << ans;
}