#include <stdio.h>


int main(){

  int n,q,S[10000],T[10000],i,count=0,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]);
      left=0;
      right=n;
      while(1){
	
      if(left>right)	break;

      mid=(left+right)/2;
      // printf("%d\n",mid);
      if(S[mid]==T[i]){
	count++;
	break;
      }
      else if(T[i]<S[mid]){
	
	right=mid;

      }
      else  left=mid+1;
      
      }
  }
  

  printf("%d\n",count);

  return 0;
}

  
  

