
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 food[] = new int[m];
		
		for(int i=0;i<n;i++) {
			int k = sc.nextInt();
			for(int j=0;j<k;j++) {
				food[sc.nextInt()-1] ++;
			}
		}
		sc.close();
		int count=0;
		for(int num : food) {
			if(num == 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 food[] = new int[m];
		
		for(int i=0;i<n;i++) {
			int k = sc.nextInt();
			for(int j=0;j<k;j++) {
				food[sc.nextInt()-1] ++;
			}
		}
		sc.close();
		int count=0;
		for(int num : food) {
			if(num == 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 food[] = new int[m];
		
		for(int i=0;i<n;i++) {
			int k = sc.nextInt();
			for(int j=0;j<k;j++) {
				food[sc.nextInt()-1] ++;
			}
		}
		sc.close();
		int count=0;
		for(int num : food) {
			if(num == n) {
				count++;
			}
		}
		System.out.println(count);
	} main {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		int food[] = new int[m];
		
		for(int i=0;i<n;i++) {
			int k = sc.nextInt();
			for(int j=0;j<k;j++) {
				food[sc.nextInt()-1] ++;
			}
		}
		sc.close();
		int count=0;
		for(int num : food) {
			if(num == 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 food[] = new int[m]; food new int[m] m for(int i=0;i<n;i++) {
			int k = sc.nextInt();
			for(int j=0;j<k;j++) {
				food[sc.nextInt()-1] ++;
			}
		} 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++) {
				food[sc.nextInt()-1] ++;
			}
		} {
			int k = sc.nextInt();
			for(int j=0;j<k;j++) {
				food[sc.nextInt()-1] ++;
			}
		} int k = sc.nextInt(); k sc.nextInt() sc.nextInt sc for(int j=0;j<k;j++) {
				food[sc.nextInt()-1] ++;
			} int j=0; int j=0; j 0 j<k j k j++ j++ j {
				food[sc.nextInt()-1] ++;
			} {
				food[sc.nextInt()-1] ++;
			} food[sc.nextInt()-1] ++ food[sc.nextInt()-1] food sc.nextInt()-1 sc.nextInt() sc.nextInt sc 1 sc.close() sc.close sc int count=0; count 0 for(int num : food) {
			if(num == n) {
				count++;
			}
		} int num food {
			if(num == n) {
				count++;
			}
		} {
			if(num == n) {
				count++;
			}
		} if(num == n) {
				count++;
			} num == n num 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 food[] = new int[m];
		
		for(int i=0;i<n;i++) {
			int k = sc.nextInt();
			for(int j=0;j<k;j++) {
				food[sc.nextInt()-1] ++;
			}
		}
		sc.close();
		int count=0;
		for(int num : food) {
			if(num == 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 food[] = new int[m];
		
		for(int i=0;i<n;i++) {
			int k = sc.nextInt();
			for(int j=0;j<k;j++) {
				food[sc.nextInt()-1] ++;
			}
		}
		sc.close();
		int count=0;
		for(int num : food) {
			if(num == 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 food[] = new int[m];
		
		for(int i=0;i<n;i++) {
			int k = sc.nextInt();
			for(int j=0;j<k;j++) {
				food[sc.nextInt()-1] ++;
			}
		}
		sc.close();
		int count=0;
		for(int num : food) {
			if(num == n) {
				count++;
			}
		}
		System.out.println(count);
	}

}
