#include<stdio.h>

int A[1000000], n;

int binary(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(binary(k)) sum++;
  } 
printf("%d\n", sum);
return 0;
}
