#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 - left) / 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 argc, char const *argv[])
{
    int q, k, sum = 0;

    scanf("%d", &n);
    for (int i = 0; i < n; i++) {
        scanf("%d", &A[i]);
    }

    scanf("%d", &q);
    for (int i = 0; i < q; i++) {
        scanf("%d", &k);
        if (binarySearch(k)) {
            sum++;
        }
    }

    printf("%d\n", sum);

    return 0;
}


