#include<stdio.h>

int A[1000000], n;

int binarySearch(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 ( binarySearch(k))
        {
            sum++;
        }
    }
    printf("%d\n", sum);

    return 0;
}
