/* Binary Search */
#include <stdio.h>

int A[1000000], n;

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

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

int main()
{
    int i, q, k, 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", &k);
        if(binarySearch(k)){ sum++; }
    }
    printf("%d\n", sum);
    return 0;
}
