#include<stdio.h>

int A[100000],n;

int binarysearcch(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(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(binarysearcch(k))sum++;
    }
    printf("%d\n",sum);
    
    return 0;
}

