#include "bits/stdc++.h"
#include<unordered_map>
#include<unordered_set>
#pragma warning(disable:4996)
using namespace std;
using ld = long double;
const ld eps = 1e-9;

//// < "d:\d_download\visual studio 2015\projects\programing_contest_c++\debug\a.txt" > "d:\d_download\visual studio 2015\projects\programing_contest_c++\debug\b.txt"


int main() {
	int N, M, A, B; cin >> N >> M >> A >> B;
	vector<int>v;
	for (int i =0 ; i < N; ++i) {
		int a; cin >> a;
		if (a >= A)v.push_back(a);
		else break;;
	}
	if (N - v.size() < M) {
		while (1) {

			if (v.empty())break;
			if (v.back() <= B)v.pop_back();
			else {
				break;
			}
		}

	}
	cout << v.size() << endl;
	return 0;
}