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

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