#include<stdio.h>

int A[1000000], n;

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

    while(left < right){
        mid = (left + left)/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 < n; i++){
        scanf("%d", &k);
        if (binarySearch(k))sum++;
    }
    printf("%d\n", sum);

    return 0;
}
