import java.util.*;

public class Main {
	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[] S = new int[n];
		
		for(int i = 0; i < n; i++){
			S[i] = sc.nextInt();
		}

		int q = sc.nextInt();
		int[] T = new int[q];

		for(int i = 0; i < q; i++){
			T[i] = sc.nextInt();
		}

		int low,mid,high,key,cnt = 0;

		for(int i = 0;i < q;i++){
			low = 0;
			high = n - 1;
			key = T[i];
			while(low <= high){
				mid = (low + high) / 2;
				if(S[mid] == key){
					cnt++;
					break;
				} else if(S[mid] < key){
					low = mid + 1;
				} else if(S[mid] > key) {
					high = mid - 1;
				}
			}
		}
		System.out.println(cnt);
	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz