import java.util.*;
 
public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        
        int N =sc.nextInt();
        int M =sc.nextInt();
        int count=0;
        int K,A;
        int ans[] =new int[M];
        
        for(int i=0; i < N; i++){
            K =sc.nextInt();
            for(int j = 0; j < K; j++){
                A =sc.nextInt();
                ans[A-1] += 1;
            }
        }
        for(int i = 0; i < M; i++){
            if(ans[i] == N){
                count += 1;
            }
        }
        System.out.println(count);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        
        int N =sc.nextInt();
        int M =sc.nextInt();
        int count=0;
        int K,A;
        int ans[] =new int[M];
        
        for(int i=0; i < N; i++){
            K =sc.nextInt();
            for(int j = 0; j < K; j++){
                A =sc.nextInt();
                ans[A-1] += 1;
            }
        }
        for(int i = 0; i < M; i++){
            if(ans[i] == N){
                count += 1;
            }
        }
        System.out.println(count);
    }
} Main public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        
        int N =sc.nextInt();
        int M =sc.nextInt();
        int count=0;
        int K,A;
        int ans[] =new int[M];
        
        for(int i=0; i < N; i++){
            K =sc.nextInt();
            for(int j = 0; j < K; j++){
                A =sc.nextInt();
                ans[A-1] += 1;
            }
        }
        for(int i = 0; i < M; i++){
            if(ans[i] == N){
                count += 1;
            }
        }
        System.out.println(count);
    } main {
        
        Scanner sc = new Scanner(System.in);
        
        int N =sc.nextInt();
        int M =sc.nextInt();
        int count=0;
        int K,A;
        int ans[] =new int[M];
        
        for(int i=0; i < N; i++){
            K =sc.nextInt();
            for(int j = 0; j < K; j++){
                A =sc.nextInt();
                ans[A-1] += 1;
            }
        }
        for(int i = 0; i < M; i++){
            if(ans[i] == N){
                count += 1;
            }
        }
        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 K K A; A int ans[] =new int[M]; ans new int[M] M for(int i=0; i < N; i++){
            K =sc.nextInt();
            for(int j = 0; j < K; j++){
                A =sc.nextInt();
                ans[A-1] += 1;
            }
        } int i=0; int i=0; i 0 i < N i N i++ i++ i {
            K =sc.nextInt();
            for(int j = 0; j < K; j++){
                A =sc.nextInt();
                ans[A-1] += 1;
            }
        } {
            K =sc.nextInt();
            for(int j = 0; j < K; j++){
                A =sc.nextInt();
                ans[A-1] += 1;
            }
        } K =sc.nextInt() K sc.nextInt() sc.nextInt sc for(int j = 0; j < K; j++){
                A =sc.nextInt();
                ans[A-1] += 1;
            } int j = 0; int j = 0; j 0 j < K j K j++ j++ j {
                A =sc.nextInt();
                ans[A-1] += 1;
            } {
                A =sc.nextInt();
                ans[A-1] += 1;
            } A =sc.nextInt() A sc.nextInt() sc.nextInt sc ans[A-1] += 1 ans[A-1] ans A-1 A 1 1 for(int i = 0; i < M; i++){
            if(ans[i] == N){
                count += 1;
            }
        } int i = 0; int i = 0; i 0 i < M i M i++ i++ i {
            if(ans[i] == N){
                count += 1;
            }
        } {
            if(ans[i] == N){
                count += 1;
            }
        } if(ans[i] == N){
                count += 1;
            } ans[i] == N ans[i] ans i N {
                count += 1;
            } count += 1 count 1 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) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        
        int N =sc.nextInt();
        int M =sc.nextInt();
        int count=0;
        int K,A;
        int ans[] =new int[M];
        
        for(int i=0; i < N; i++){
            K =sc.nextInt();
            for(int j = 0; j < K; j++){
                A =sc.nextInt();
                ans[A-1] += 1;
            }
        }
        for(int i = 0; i < M; i++){
            if(ans[i] == N){
                count += 1;
            }
        }
        System.out.println(count);
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        
        int N =sc.nextInt();
        int M =sc.nextInt();
        int count=0;
        int K,A;
        int ans[] =new int[M];
        
        for(int i=0; i < N; i++){
            K =sc.nextInt();
            for(int j = 0; j < K; j++){
                A =sc.nextInt();
                ans[A-1] += 1;
            }
        }
        for(int i = 0; i < M; i++){
            if(ans[i] == N){
                count += 1;
            }
        }
        System.out.println(count);
    }
} Main
import java.util.*;
 
public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        
        int N =sc.nextInt();
        int M =sc.nextInt();
        int count=0;
        int K,A;
        int ans[] =new int[M];
        
        for(int i=0; i < N; i++){
            K =sc.nextInt();
            for(int j = 0; j < K; j++){
                A =sc.nextInt();
                ans[A-1] += 1;
            }
        }
        for(int i = 0; i < M; i++){
            if(ans[i] == N){
                count += 1;
            }
        }
        System.out.println(count);
    }
}