#include <stdio.h>

int binarySearch(int A[],int n,int key){
  int left =0,right,mid;
  right=n;
  while(left < right){
    mid = (left+right)/2;
    if(A[mid] == key)return 1;
    else if(key < A[mid])right =mid;
    else left=mid+1;
  }
  return 0;
}
int main(){
  int i,n,S[10000],q,key,count=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",&key);
    if(binarySearch(S,n,key) == 1)count++;
      }
  printf("%d\n",count);
  return 0;
}

