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[] food = new int[M+1];
    	for (int i = 0; i < N; i++) {
    		int K = sc.nextInt();
    		for (int j = 0; j < K; j++) {
    			food[sc.nextInt()]++;
    		}
    	}
    	int count = 0;
    	for (int score : food) {
    		if (score == 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[] food = new int[M+1];
    	for (int i = 0; i < N; i++) {
    		int K = sc.nextInt();
    		for (int j = 0; j < K; j++) {
    			food[sc.nextInt()]++;
    		}
    	}
    	int count = 0;
    	for (int score : food) {
    		if (score == 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+1];
    	for (int i = 0; i < N; i++) {
    		int K = sc.nextInt();
    		for (int j = 0; j < K; j++) {
    			food[sc.nextInt()]++;
    		}
    	}
    	int count = 0;
    	for (int score : food) {
    		if (score == 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+1];
    	for (int i = 0; i < N; i++) {
    		int K = sc.nextInt();
    		for (int j = 0; j < K; j++) {
    			food[sc.nextInt()]++;
    		}
    	}
    	int count = 0;
    	for (int score : food) {
    		if (score == 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+1]; food new int[M+1] M+1 M 1 for (int i = 0; i < N; i++) {
    		int K = sc.nextInt();
    		for (int j = 0; j < K; j++) {
    			food[sc.nextInt()]++;
    		}
    	} 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()]++;
    		}
    	} {
    		int K = sc.nextInt();
    		for (int j = 0; j < K; j++) {
    			food[sc.nextInt()]++;
    		}
    	} int K = sc.nextInt(); K sc.nextInt() sc.nextInt sc for (int j = 0; j < K; j++) {
    			food[sc.nextInt()]++;
    		} int j = 0; int j = 0; j 0 j < K j K j++ j++ j {
    			food[sc.nextInt()]++;
    		} {
    			food[sc.nextInt()]++;
    		} food[sc.nextInt()]++ food[sc.nextInt()] food sc.nextInt() sc.nextInt sc int count = 0; count 0 for (int score : food) {
    		if (score == N) {
    			count++;
    		}
    	} int score food {
    		if (score == N) {
    			count++;
    		}
    	} {
    		if (score == N) {
    			count++;
    		}
    	} if (score == N) {
    			count++;
    		} score == N score 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+1];
    	for (int i = 0; i < N; i++) {
    		int K = sc.nextInt();
    		for (int j = 0; j < K; j++) {
    			food[sc.nextInt()]++;
    		}
    	}
    	int count = 0;
    	for (int score : food) {
    		if (score == 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+1];
    	for (int i = 0; i < N; i++) {
    		int K = sc.nextInt();
    		for (int j = 0; j < K; j++) {
    			food[sc.nextInt()]++;
    		}
    	}
    	int count = 0;
    	for (int score : food) {
    		if (score == 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[] food = new int[M+1];
    	for (int i = 0; i < N; i++) {
    		int K = sc.nextInt();
    		for (int j = 0; j < K; j++) {
    			food[sc.nextInt()]++;
    		}
    	}
    	int count = 0;
    	for (int score : food) {
    		if (score == N) {
    			count++;
    		}
    	}
    	System.out.println(count);
    }
}