import java.util.ArrayList;
import java.util.Scanner;

public class Neko {
    public static void main(String[] args) {
        Scanner read = new Scanner(System.in);
        int n = read.nextInt();
        int m = read.nextInt();
        ArrayList<Integer> chess=new ArrayList<>();
        for (int i = 0; i < n; i++) {
            chess.add(read.nextInt());
        }
        int ans=0;
        for (int i = 0; i < m; i++) {
            int keys = read.nextInt();
            for (int j = 0; j < chess.size(); j++) {
                if ((chess.get(j)+keys)%2!=0) {
                    ans+=1;
                    chess.remove(j);
                    break;
                }
            }
        }
        System.out.println(ans);
    }
}