#!/usr/bin/env python
# -*- coding:utf-8 -*-
#from __future__ import print_function
import time
import sys
import io
import re
import math
start = time.clock()
i = 0
n=input()
S=map(int, raw_input().split())
q=input()
T=map(int, raw_input().split())
#s=sorted(set(S), key=S.index)
print len(set(S)&set(T))