#include<stdio.h>

 int binary(int n,int S[],int T){
          int i,mid,left,right;
          left=0;right=n;
          while(left<right){
                mid=(left+right)/2;
                if(S[mid]==T)return mid;
                else if(T<S[mid]){
                         right=mid;
                         }
                else {left=mid+1;}
                }
          return 0;
          }



 int main(){
       int i,n,q,S[100001],T,cnt=0;
       scanf("%d",&n);
       for(i=0;i<n;i++){
                 scanf("%d",&S[i]);
                 }
       scanf("%d",&q);
       for(i=0;i<q;i++){
                 scanf("%d",&T);
                 if(binary(n,S,T))cnt++;
                 }
       printf("%d\n",cnt);
       return 0;
       }

