import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        int n = scan.nextInt();
        int m = scan.nextInt();

        BitSet master = new BitSet(m);
        master.set(1, m + 1);
        for (int i = 0; i < n; ++i) {
            int k = scan.nextInt();

            BitSet bitset = new BitSet(m);
            for (int j = 0; j < k; ++j) {
                bitset.set(scan.nextInt());
            }
            master.and(bitset);
        }
        System.out.println(master.cardinality());
    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz