#include<stdio.h>


int main()
{
    int n,m,p,q,r,i;
    int count=0;
    int t[15000];
    int k;
    scanf("%d",&n);
    for(i=0;i<n;i++)
        scanf("%d",&t[i]);

  scanf("%d",&m);

    for(i=0;i<m;i++)
    {
        scanf("%d",&k);
        p=0;
        r=n-1;
        while(p<=r)
         {
              q=(p+r)/2;
               if(t[q]==k)
               {
                count++;
                p=q+1;

            }
            else if(t[q]<k)
                p=q+1;
            else
                r=q-1;
        }


    }

    printf("%d\n",count);

    return 0;
}