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

