def binarySearch(key, arr, N):
    left = 0
    right = N
    while left < right:
        mid = (left + right) // 2
        if arr[mid] == key:
            return 1
        elif key < arr[mid]:
            right = mid
        else:
            left = mid + 1
    return 0


N1 = int(input())
arr1 = [int(n) for n in input().split()]
N2 = int(input())
arr2 = [int(n) for n in input().split()]

print(sum([binarySearch(key, arr1, N1) for key in arr2]))

