#include <stdio.h>

int S[100001], n;

int binarySearch(int key) {
    int left = 0;
    int right = n;

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

int main()
{
    int q, i;
    int T, ans = 0;

    scanf("%d", &n);

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

    scanf("%d", &q);

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

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

    return 0;
}