import java.util.*;
public class Main {
	public static void main(String[] args){
       Scanner sc = new Scanner(System.in);   
       //取得
      int N = sc.nextInt();
      int m = sc.nextInt();
      int[] M = new int[30];
      for(int i=0;i<N;i++){
        int K = sc.nextInt();
        int[] A = new int[K];
        for(int j=0;j<K;j++){
          A[j] = sc.nextInt();
          M[A[j]-1]++;
        }
      }
      int count=0;
      for(int i=0;i<30;i++){
        if(M[i]==N){
          count++;
        }
      }
      System.out.println(count);
    }
}
/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