#include<stdio.h>
#include<math.h>
int main(void) {
    int n, i, j, s[100000], q, t[50000], count = 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 ( j = 0; j < n; j++ ) {
            if ( t[i] == s[j] ) {count++; break;}
        }
    }
    printf("%d\n", count);
    return 0;
}