#include<stdio.h>

int A[100000], n;

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

int main()
{
    int i, 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 (binarySearch(key) == 1) {
            sum++;
        }
    }
    printf("%d\n", sum);
    return 0;
}