#include <stdio.h>

int A[10000],n;

int binarysearch(int key){
    int left=0,right=n,mid;
    
    while(left<right){
        mid=(left+right)/2;
        if(key==A[mid])
            return 1;
        if(key>A[mid])
            left=mid+1;
        else if(key<A[mid])
            right=mid;
    }
    
    return 0;
}

int main(){
    int i,q,keynum,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",&keynum);
        if(binarysearch(keynum))
            sum++;
    }
    
    printf("%d\n",sum);
    
    return 0;
}