import java.util.*;

class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int a = sc.nextInt();
        int b = sc.nextInt();
        int x[] = new int[b];
        for (int i=0;i<a;i++){
            int c = sc.nextInt();
            for (int j=0;j<c;j++){
                int d = sc.nextInt();
                x[d-1]=x[d-1]+1;
                //System.out.println("i="+i + ",j="+j + ","+d);
                
            }
            //System.out.println("--");
        }
        int ret = 0;
        for (int k=0;k<b;k++){
            if (a==x[k]) ret=ret+1;
            //System.out.println(k+1 + ":" + a +"=" + x[k]);
        }
        System.out.println(ret);

    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz