import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int n, q, x, y,count;
        int sum=0;
        n = sc.nextInt();
        q = sc.nextInt();
        int[][] a = new int[n][];

        for (int i = 0; i < n; i++) {
            count=sc.nextInt();
            a[i]=new int[count];
            for (int j = 0; j<count; j++) {
                a[i][j] = sc.nextInt();
            }
        }

        for (int i = 0; i < q; i++) {
            x = sc.nextInt();
            y = sc.nextInt();
            sum^= a[x - 1][y - 1];
        }
        System.out.println(sum);
    }
}