#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(int 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;
}
