#include<stdio.h>
int a[1000000],n;
int binarysearch(int key)
{
    int left=0;
    int right=n;
    int mid;
    while(left<right)
    {
        mid=(left+right)/2;
        if(key==a[mid]) return 1;
        if(key>mid) left=mid+1;
        else if(key<a[mid]) right=mid;
    }
    return 0;
}
int main()
{
    int i,q,k,sum=0;
    scanf("%d",&n);
    for(i=0;i<n;i++)
    {
        scanf("%d",&a[i]);
    }
    scanf("%d",&q);
    for(i=0;i<q;i++)
    {
        scanf("%d",&k);
        if(binarysearch(k)) sum++;
    }
    printf("%d\n",sum);
    return 0;
}