#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(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;
}
