import java.util.Scanner;
class Main{
	public static void main(String[]args) {
		Scanner sc=new Scanner(System.in);
		int a=sc.nextInt();
		int b=sc.nextInt();
		int c[]=new int[b];
		for(int i=0;i<a;i++) {
			int d=sc.nextInt();
			for(int j=0;j<d;j++) {
				int e=sc.nextInt();
				c[e-1]++;
			}
		}
		int ans=0;
		for(int i=0;i<b;i++) {
			if(c[i]==a) {
				ans++;
			}
		}
		System.out.println(ans);
	}
}
/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