#include<stdio.h>

// 線形探索
int search(int A[], int n, int key) {
    int i=0;
    A[n] = key;
    while (A[i] != key) i++;
    return i != n;
}

int main() {
    int i, n, A[10000+1], q, key, 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", &key);
        if (search(A, n, key)) sum++;
    }
    printf("%d\n", sum);

    return 0;
}
