#include < iostream >
using   namespace  std;

int  N,M;
int  a[ 15000 ];
int  main()
{
    scanf( " %d " , & N);
     for ( int  i = 0 ;i < N; ++ i)
        scanf( " %d " , & a[i]);
     int  s = 0 ,x;
    scanf( " %d " , & M);
     while (M -- ){
        scanf( " %d " , & x);
         int  l = 0 ,r = N - 1 ;
         while (l <= r){
             int  mid = (l + r) >> 1 ;
             if (a[mid] == x)  break ;
             else   if (a[mid] > x) r = mid - 1 ;
             else  l = mid + 1 ;
        }
         if (l <= r) s ++ ;
    }
    printf( " %d\n " ,s);
     return   0 ;
}