#include <stdio.h>
int main(){
    
    int i,n,q,count=0;
    int S[10000],T[500];  
    int left,right,mid;

    scanf("%d",&n);

for(i=0;i<n;i++){
    scanf("%d",&S[i]);
}

scanf("%d",&q);

for(i=0;i<q;i++){
    scanf("%d",&T[i]);
}

for(i=0;i<q;i++){
    left=0;
    right=n;
 while(left<right){
   mid=(left+right)/2;
   if(S[mid]==T[i]){
       count++;
       break;
   }  
   else if(T[i] < S[mid]) right=mid;
   else left=mid+1;
 }
}

printf("%d\n",count);

return 0;

}