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

int main(){

  int i,j,q,count=0;
  int left,right;
  int T[Q];
  int S[N];
  int n;
  int mid;
  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++){
       left=0;
       right=n;
       while(left < right){
	 mid = (left + right) / 2;
	 
	 if(S[mid] == T[j]){
	   count++;
	   break;
	 }
	 else if(T[j] < S[mid])
	   right = mid;
	 
	 else left = mid + 1;
       }
    }

    printf("%d\n",count);
    return 0;
}