import java.util.Arrays;
import java.util.Scanner;

public class Main {
    public static void main(String args[]) {
        try (Scanner in = new Scanner(System.in)) {
            int N = in.nextInt();
            int M = in.nextInt();
            int likeAll = ((1 << M) - 1);
            for (int i = 0; i < N; i++) {
                int K = in.nextInt();
                int like = 0;
                for (int j = 0; j < K; j++) {
                    int A = in.nextInt() - 1;
                    like |= (1 << A);
                }
                likeAll &= like;
            }

            System.out.println(Integer.bitCount(likeAll));
        }
    }
}

/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