#include<stdio.h>
int A[100000],n;
int binarySearch(int key){
    int left=0, right=n,mid;
    while(left<right){
        mid=(left+right)/2;
        if(A[mid]==key) return 1;
        else if(key<A[mid]) right=mid;
        else left=mid+1;
    }
    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;
    
    
}
