#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 > a[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;
    }