#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,qnk,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;
}