#define NOT_FOUND 20000
 
#include <stdio.h>
 

int linearSearch(int key, int *t, int n);
 
int main(void) {
    int s[10001] = {};
    int t[501] = {};
    int n = 0;
    int q = 0;
    int k = 0;
    int i = 0;
    int j = 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[i]);
 
    for (i = 0; i < q; i++) {
        if (linearSearch(t[i], s, n) != NOT_FOUND)
            k++;
    }
 
    printf("%d\n", k);
 
    return 0;
}
 

int linearSearch(int key, int *s, int n) {
    int i = 0;
 
    s[n] = key;
 
    while (s[i] != key) {
        i++;
    }
 
    if (i == n)
        return NOT_FOUND;
 
    return i;
}