#include<stdio.h>

int A[1000000], n;

int binarySearch(int key){
	int left = 0;
	int right = n;
	int mid;
	while( left < right ){
		mid = (left+right)/2;
		if( key == A[mid] )return 1;
		if( key > A[mid] )left = mid + 1;
		else if ( key < A[mid] )right = mid;
	}
	return 0;
}

int main(){
	int i, q, k, sum = 0;
	
	scanf("%d", &n);
	for(i=0;i<n;i++){
		scanf("%d",&A[i]);
	}
	scanf("%d", &q);
	for(i=0;i<q;i++){
		scanf("%d",&k);
		if( binarySearch(k)) sum++;
	}
	printf("%d\n", sum);
	
	return 0;
}

