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

        for (int i = 0; i < n; i++) {
            int kinds = sc.nextInt();
            for (int j = 0; j < kinds; j++) {
                if (++survey[sc.nextInt()] == n) count++;
            }
        }
        System.out.println(count);
    }
} import java.util.Scanner; Scanner 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 count = 0;
        int[] survey = new int[m+1];

        for (int i = 0; i < n; i++) {
            int kinds = sc.nextInt();
            for (int j = 0; j < kinds; j++) {
                if (++survey[sc.nextInt()] == 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 count = 0;
        int[] survey = new int[m+1];

        for (int i = 0; i < n; i++) {
            int kinds = sc.nextInt();
            for (int j = 0; j < kinds; j++) {
                if (++survey[sc.nextInt()] == n) count++;
            }
        }
        System.out.println(count);
    } main {
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        int m = sc.nextInt();

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

        for (int i = 0; i < n; i++) {
            int kinds = sc.nextInt();
            for (int j = 0; j < kinds; j++) {
                if (++survey[sc.nextInt()] == 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 count = 0; count 0 int[] survey = new int[m+1]; survey new int[m+1] m+1 m 1 for (int i = 0; i < n; i++) {
            int kinds = sc.nextInt();
            for (int j = 0; j < kinds; j++) {
                if (++survey[sc.nextInt()] == n) count++;
            }
        } int i = 0; int i = 0; i 0 i < n i n i++ i++ i {
            int kinds = sc.nextInt();
            for (int j = 0; j < kinds; j++) {
                if (++survey[sc.nextInt()] == n) count++;
            }
        } {
            int kinds = sc.nextInt();
            for (int j = 0; j < kinds; j++) {
                if (++survey[sc.nextInt()] == n) count++;
            }
        } int kinds = sc.nextInt(); kinds sc.nextInt() sc.nextInt sc for (int j = 0; j < kinds; j++) {
                if (++survey[sc.nextInt()] == n) count++;
            } int j = 0; int j = 0; j 0 j < kinds j kinds j++ j++ j {
                if (++survey[sc.nextInt()] == n) count++;
            } {
                if (++survey[sc.nextInt()] == n) count++;
            } if (++survey[sc.nextInt()] == n) count++; ++survey[sc.nextInt()] == n ++survey[sc.nextInt()] survey[sc.nextInt()] survey sc.nextInt() sc.nextInt sc n 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 count = 0;
        int[] survey = new int[m+1];

        for (int i = 0; i < n; i++) {
            int kinds = sc.nextInt();
            for (int j = 0; j < kinds; j++) {
                if (++survey[sc.nextInt()] == 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 count = 0;
        int[] survey = new int[m+1];

        for (int i = 0; i < n; i++) {
            int kinds = sc.nextInt();
            for (int j = 0; j < kinds; j++) {
                if (++survey[sc.nextInt()] == n) count++;
            }
        }
        System.out.println(count);
    }
} Main
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 count = 0;
        int[] survey = new int[m+1];

        for (int i = 0; i < n; i++) {
            int kinds = sc.nextInt();
            for (int j = 0; j < kinds; j++) {
                if (++survey[sc.nextInt()] == n) count++;
            }
        }
        System.out.println(count);
    }
}