import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner reader = new Scanner(System.in);
    Scanner nLine = new Scanner(reader.nextLine());
    int n = nLine.nextInt();
    int m = nLine.nextInt();
    int[] unique = new int[31];
    int count = 0;
    while(reader.hasNextLine()) {
      Scanner line = new Scanner(reader.nextLine());
      int base = line.nextInt();
      while(base > 0) {
        int i = line.nextInt();
        unique[i]++;
        base--;
      }
    }

    for(int i = 0; i <= m; ++i) {
      if(unique[i] == n) {
        count++;
      }
    }
    System.out.print(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