import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.IOException;

public class Main {
  public static void main(String[] args) throws IOException {
    BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
    String[] str = in.readLine().split(" ");
    int n = Integer.parseInt(str[0]);
    int m = Integer.parseInt(str[1]);
    int a[] = new int[m];
    for(int i=0; i<n; i++) {
      str = in.readLine().split(" ");
      int k = Integer.parseInt(str[0]);
      for(int j=1; j<=k; j++) {
        int t = Integer.parseInt(str[j]);
        a[t-1]++;
      }
    }
    
    int count = 0;
    for(int i=0; i<m; i++) {
      if(a[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