import java.util.Scanner;

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