#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 
            right=mid;
    }
    return 0;
}

int main(void){
    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;
}