#include<stdio.h>

int A[100000], 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]) right=mid;
    else if(key>A[mid]) left=mid+1;
  }
  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;
}