#include <stdio.h>

int where ( int a[], int n, int b, int c){
  int x = -1;
  for ( int i = b; i < c; ++i ){
    if ( a[i] == n ){
      x = i;
    }
  }
  return x;
}

int main()
{
 int num = 0;
 int s[100000], t[50000];
 int ns, nt, i, a;

 scanf("%d", &ns);
 for ( i = 0; i < ns; ++i ){
   scanf("%d", &s[i]);
   for ( int j = 0; j < i; ++j ){
     if ( s[i] == s[j] ){
       s[i] = -2;
     }
   }
 }

 scanf("%d", &nt);
 for ( i = 0; i < nt; ++i ){
   scanf("%d", &t[i]);
   a = where( s, t[i], t[i]-1, ns);
   if ( a < 0 ){
     a = 0;
   }
   for ( int j = a; j < ns; ++j ){
     if ( t[i] == s[j] ){
       num++;
     }
   }
 }

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

 return 0;
}
