import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int m = sc.nextInt();
    int[][] suki = new int[n][m];
    for(int i = 0; i < n; i++) {
      int k = sc.nextInt();
      for(int j = 0; j < k; j++) {
        int r = sc.nextInt() - 1;
        suki[i][r]++;  
      }
    }
    int ans = 0;
    for(int j = 0; j < m; j++) {
      int p = 1;
      for(int i = 0; i < n; i++) {
        if(suki[i][j] == 0) p = 0;
      }
      if(p == 1) 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