#include<stdio.h>

#define N 10000
int main(){
  int n, q;
  int i, j, key;
  int S[N], T[N];
  int count = 0;
  
  scanf("%d", &n);
 
  for(i = 0; i < n; i++){
    scanf("%d", &S[i]);
  }
  

  scanf("%d", &q);

  for(i = 0; i < q; i++){
    scanf("%d", &T[i]);
  }

  for(i = 0; i < q; i++){
    key = T[i];

    j = 0;

    S[n] = key;

    while(S[j] != key)
      j++;

    if(j != n) count++;
  }
  
  printf("%d\n", count);
  
  return 0;
}