#include<stdio.h>
#include<stdlib.h>
#define N 10000

int main(){

  int n, q, i, j, cnt=0, key, right, left, mid;
  int s[N], t[N];

  scanf("%d",&n);

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

  for(i=0;i<q;i++){
    scanf("%d",&t[i]);
  }
  for(j=0;j<q;j++){
    key=t[j];
    left=0;
    right=n;
    while(left<right){
      mid=(left+right)/2;
      if(s[mid]==key){
	cnt++;
	break;
      }
      else if(key<s[mid])right=mid;
      else left=mid+1;
    }
  }
  printf("%d\n",cnt);

  return 0;
}