контролно

import java.util.Scanner;

public class Main {

    public static void main(String[] args) {
	    Scanner in = new Scanner(System.in);
        int students = in.nextInt();
        int l = in.nextInt();
        int r = in.nextInt();

        int[] noPen = new int[l];
        int[] wPen = new int[r];

        for (int i = 0; i < l; i++) {
            noPen[i] = in.nextInt();
        }
        for (int i = 0; i < r; i++) {
            wPen[i] = in.nextInt();
        }

        int countGivenPens = 0;
        for (int i = 0; i < wPen.length; i++) {
            for (int j = 0; j < noPen.length; j++) {
                if (wPen[i] == noPen[j] + 1 || wPen[i] == noPen[j] - 1) {
                    noPen[j] = -1;
                    countGivenPens++;
                    break;
                }
            }
        }
        int studentsWPen = students - noPen.length;
        System.out.println(students - studentsWPen - countGivenPens);
    }
}