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 data[] = new int[m+1];
    int count = 0;

    for (int i = 0; i < n; i++) {
      int k = sc.nextInt();
      for (int j = 0; j < k; j++) {
        int a = sc.nextInt();
        data[a]++;
      }
    }

    for (int i = 0; i < m+1; i++) {
      if (data[i] == n) {
        count++;
      }
    }

    System.out.println(count);

  }

} import java.util.*; util.* java public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int m = sc.nextInt();
    int data[] = new int[m+1];
    int count = 0;

    for (int i = 0; i < n; i++) {
      int k = sc.nextInt();
      for (int j = 0; j < k; j++) {
        int a = sc.nextInt();
        data[a]++;
      }
    }

    for (int i = 0; i < m+1; i++) {
      if (data[i] == n) {
        count++;
      }
    }

    System.out.println(count);

  }

} Main public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int m = sc.nextInt();
    int data[] = new int[m+1];
    int count = 0;

    for (int i = 0; i < n; i++) {
      int k = sc.nextInt();
      for (int j = 0; j < k; j++) {
        int a = sc.nextInt();
        data[a]++;
      }
    }

    for (int i = 0; i < m+1; i++) {
      if (data[i] == n) {
        count++;
      }
    }

    System.out.println(count);

  } main {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int m = sc.nextInt();
    int data[] = new int[m+1];
    int count = 0;

    for (int i = 0; i < n; i++) {
      int k = sc.nextInt();
      for (int j = 0; j < k; j++) {
        int a = sc.nextInt();
        data[a]++;
      }
    }

    for (int i = 0; i < m+1; i++) {
      if (data[i] == n) {
        count++;
      }
    }

    System.out.println(count);

  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) int n = sc.nextInt(); n sc.nextInt() sc.nextInt sc int m = sc.nextInt(); m sc.nextInt() sc.nextInt sc int data[] = new int[m+1]; data new int[m+1] m+1 m 1 int count = 0; count 0 for (int i = 0; i < n; i++) {
      int k = sc.nextInt();
      for (int j = 0; j < k; j++) {
        int a = sc.nextInt();
        data[a]++;
      }
    } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
      int k = sc.nextInt();
      for (int j = 0; j < k; j++) {
        int a = sc.nextInt();
        data[a]++;
      }
    } {
      int k = sc.nextInt();
      for (int j = 0; j < k; j++) {
        int a = sc.nextInt();
        data[a]++;
      }
    } int k = sc.nextInt(); k sc.nextInt() sc.nextInt sc for (int j = 0; j < k; j++) {
        int a = sc.nextInt();
        data[a]++;
      } int j = 0; int j = 0; j 0 j < k j k j++ j++ j {
        int a = sc.nextInt();
        data[a]++;
      } {
        int a = sc.nextInt();
        data[a]++;
      } int a = sc.nextInt(); a sc.nextInt() sc.nextInt sc data[a]++ data[a] data a for (int i = 0; i < m+1; i++) {
      if (data[i] == n) {
        count++;
      }
    } int i = 0; int i = 0; i 0 i < m+1 i m+1 m 1 i++ i++ i {
      if (data[i] == n) {
        count++;
      }
    } {
      if (data[i] == n) {
        count++;
      }
    } if (data[i] == n) {
        count++;
      } data[i] == n data[i] data i n {
        count++;
      } count++ count System.out.println(count) System.out.println System.out System System.out count String[] args args public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int m = sc.nextInt();
    int data[] = new int[m+1];
    int count = 0;

    for (int i = 0; i < n; i++) {
      int k = sc.nextInt();
      for (int j = 0; j < k; j++) {
        int a = sc.nextInt();
        data[a]++;
      }
    }

    for (int i = 0; i < m+1; i++) {
      if (data[i] == n) {
        count++;
      }
    }

    System.out.println(count);

  }

} public class Main {

  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int m = sc.nextInt();
    int data[] = new int[m+1];
    int count = 0;

    for (int i = 0; i < n; i++) {
      int k = sc.nextInt();
      for (int j = 0; j < k; j++) {
        int a = sc.nextInt();
        data[a]++;
      }
    }

    for (int i = 0; i < m+1; i++) {
      if (data[i] == n) {
        count++;
      }
    }

    System.out.println(count);

  }

} Main
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 data[] = new int[m+1];
    int count = 0;

    for (int i = 0; i < n; i++) {
      int k = sc.nextInt();
      for (int j = 0; j < k; j++) {
        int a = sc.nextInt();
        data[a]++;
      }
    }

    for (int i = 0; i < m+1; i++) {
      if (data[i] == n) {
        count++;
      }
    }

    System.out.println(count);

  }

}
