def stud_both_papers(a,b):
    return len(a.intersection(b))  #a&b



if __name__ == '__main__':
    n = int(input())
    set1 = set(map(int,input().split()))
    b = int(input())
    set2 = set(map(int,input().split()))
    
    print(stud_both_papers(set1,set2))