#include <iostream>
#include <vector>
#include <queue>
using namespace std;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N, K, M, C;
    cin >> N >> K >> M >> C;
    vector<int> starts(C);
    for (int i = 0; i < C; i++){
        cin >> starts[i];
    }


    int accepted = 0;

    priority_queue<int, vector<int>, greater<int>> heap;

    for (int i = 0; i < C; i++){
        int s = starts[i];
        int f = s + M - 1;

        while(!heap.empty() && heap.top() < s) {
            heap.pop();
        }

        if (heap.size() < (size_t)N) {
            heap.push(f);
            accepted++;
        }

    }

    cout << accepted << "\n";

    return 0;
}