#include<stdio.h>
??
main(){
??
????int i,j,n,q,left,right,S[100001],T[50001],U[50001],mid;
????int sumcount = 0;
????????
????scanf("%d",&n);
????????
????for(i = 0; i < n; i++){
????????scanf("%d",&S[i]);
????}
????????
????scanf("%d",&q);
????????
????for(j = 0; j < q; j++){
????????scanf("%d",&T[j]);
????}
??
??????
????for(j = 0; j < q; j++){
??????????
????????left = 0;
????????right = n;?????? 
??????????
????????while(left != mid || right != mid){
??????????????
????????mid = (left + right) / 2;
??
????????????if(S[mid] < T[j]) {
????????left =?? mid + 1;
????????????} else if(S[mid] > T[j]) {
????????right =?? mid;
????????????} else if(S[mid] == T[j]) {
????????sumcount++;
????????break;
????????????}
??
????????}
??????????
????}
??????
????printf("%d\n",sumcount);
??????
????return 0;
??
}