#include<stdio.h>

int A[1000000],n;

int binarySearch(int key){
    int left = 0;
    int right = 0;
    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;
}
