// Arup Guha
// 2/22/2017
// Solution to 2017 February USACO Silver Problem: Why Did the Cow Cross the Road? (helpcross)

import java.util.*;
import java.io.*;

public class helpcross {

	public static void main(String[] args) throws Exception {

		// Read input.
		Scanner stdin = new Scanner(new File("helpcross.in"));
		int n = stdin.nextInt();
		int m = stdin.nextInt();

		animal[] all = new animal[m+n];

		// Read in chickens first.
		for (int i=0; i<n; i++) {
			int t = stdin.nextInt();
			all[i] = new animal(t, t, false);
		}

		// Then cows.
		for (int i=n; i<n+m; i++) {
			int s = stdin.nextInt();
			int e = stdin.nextInt();
			all[i] = new animal(s, e, true);
		}

		// Sort all.
		Arrays.sort(all);

		int res = 0;
		PriorityQueue<Integer> pq = new PriorityQueue<Integer>();

		// Go through all animal's start times.
		for (int i=0; i<all.length; i++) {

			// If it's a cow, add it to our list of cows waiting to get help from chickens.
			if (all[i].isCow)
				pq.offer(all[i].end);

			// We get a chicken!
			else {

				// Get rid of cows who are no longer avaiable.
				while (pq.size() > 0 && pq.peek() < all[i].start) pq.poll();

				// This chicken can help a cow!
				if (pq.size() > 0) {
					res++;

					// We greedily remove the cow who is available the least.
					pq.poll();
				}

			}
		}

		// Output the result.
		PrintWriter out = new PrintWriter(new FileWriter("helpcross.out"));
		out.println(res);
		out.close();
		stdin.close();
	}
}

class animal implements Comparable<animal> {
	public int start;
	public int end;
	public boolean isCow;

	public animal(int s, int e, boolean b) {
		start = s;
		end = e;
		isCow = b;
	}

	public int compareTo(animal other) {
		if (this.start != other.start)
			return this.start - other.start;
		if (this.isCow && !other.isCow) return -1;
		if (!this.isCow && other.isCow) return 1;
		return 0;
	}
}