#include <stdio.h>

int linearSearch(int S[],int n,int key){
  int i = 0;
  S[n] = key;
  while(S[i] != key) i++;
  return i != n;
}

int main(){
  int i,n,S[10000+1],q,key,sum=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(linearSearch(S,n,key)) sum++;
  }
  printf("%d\n",sum);

  return 0;
}