import java.util.Scanner;

public class Main {

	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		int n = Integer.parseInt(sc.next());
		int m = Integer.parseInt(sc.next());
		int[] result = new int[m];
		for (int i = 0; i < n; i++) {
			int k = Integer.parseInt(sc.next());
			for (int j = 0; j < k; j++) {
				result[Integer.parseInt(sc.next()) - 1]++;
			}
		}
		int ans = 0;
		for (int i = 0; i < result.length; i++) {
			if (result[i] == n) {
				ans++;
			}
		}
		System.out.println(ans);
		sc.close();
	}
}
/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