#include <stdio.h>
#include <string.h>
#include <stdlib.h>
 
int main(void){
    int i, n, q, count = 0;
    int mid, right, left;
    int s[100001], t[5001];
 
    scanf("%d", &n);
    for(i = 0; i < n; i++) {
        scanf("%d", &s[i]);
    }
 
    scanf("%d", &q);
    for(i = 0; i < n; i++) {
        scanf("%d", &t[i]);
    }

 
    for(i = 0; i<q; i++){

       right = n;
       left = 0;
 
    while(left <= right){

         mid = (right + left) / 2;
         if(s[mid] == t[i]) {
              count++;
              break;
       }
        else if(s[mid] < t[i]){
             left = mid + 1;
       }
       else if(s[mid] > t[i]){
             right = mid - 1;
        }
 
     }
  }
    printf("%d\n", count);
 
    return 0;
}