#include <stdio.h>

int A[1000000], n;

int binary(int);

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

int binary(int key)
{
    int left = 0, right = n, mid;
    while (left < right)
    {
        mid = (right + left) / 2;
        if (key == A[mid])
            return 1;
        else if (key < A[mid])
            right = mid;
        else if (key > A[mid])
            left = mid + 1;
    }
    return 0;
}
