#include<stdio.h>
#define SMAX 100000
#define TMAX 50000

main(){
  int i,j,n,q,count = 0;
  int S[SMAX],T[TMAX];
  int left,right,mid;
  
  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(i = 0;i < q;i++){
    left = 0;
    right = n;
    while(left < right){
      mid = (left + right)/2;
      if(S[j] == T[mid]){
	count++;
	break;
      }
      else if(S[j] > T[mid]) {
	left = mid + 1;
      }
      else{
	right = mid;
      }
    }
  
  printf("%d\n",count);
  
  return 0;
}