import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc=new Scanner(System.in);
		int n=sc.nextInt(),m=sc.nextInt();
		int[] like = new int[m];
		int ans=0;

		for(int i=0;i<n;i++) {
			int k=sc.nextInt();
			for(int j=0;j<k;j++) {
				int num = sc.nextInt();
				like[num-1]+=1;
			}
		}

		for(int a : like) {
			if(a==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