#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <stdlib.h>
#define MINN 10000000000
using namespace std;


int N, M, A, Q;

vector<int> pages;


int main() {
    freopen("cheating.in","r",stdin);
    freopen("cheating.out","w",stdout);

    cin >> N >> M >> A >> Q;
    for (int i = 0; i < N; i++)
    {
        cin >> pages[i];
    }

    if (N == 1) {
        cout << 1 << '\n';
    }

    

    

    return 0;
}