#include <stdio.h>

#define x 100

int main(){

  int n,q,S[x],T[x],left,right,mid;
  int i,j,c=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",&T[i]);
  } 
  for(i=0;i<q;i++){

    left=0;
    right = n;  

    while(left<right){

      mid = (left + right)/2;

      if(S[mid]==T[i]){
	c++;
	break;
      }
      else if(T[i]<S[mid]){
	right = mid;
      }
      else if(T[i]>S[mid]) left = mid + 1;
    }
    
  }
  printf("%d\n",c);
  return 0;
}