#include <stdio.h>
#define N 100000
#define Q 500

int binary(int);
int S[N];
int n;
int mid;

int main(){
  int i,j,q,count=0;
  int T[Q];

  scanf("%d",&n);
  for(i=0;i<n;i++){
    scanf("%d",&S[i]);
  }

  scanf("%d",&q);
  for(j=0;j<q;j++){
    scanf("%d",&T[j]);
  }
    for(j=0;j<q;j++){
      if(binary(T[j]) == mid)
	count++;
    }
  printf("%d",count);
  return 0;
}

int binary(int key){
  int left=0;
  int right=n;

  while(left < right){
    mid = (left + right) / 2;

    if(S[mid] == key)
      return mid;

    else if(key < S[mid])
      right = mid;

    else left = mid + 1;
  }
  return 1;
}