#include <stdio.h>

void sort(int n, int a[n]);
int main(){
  int n,q;
  int S[10000], T[500];
  int count=0;
  int i,j;
  int si;
  scanf("%d", &n );
  //printf("%d\n", n);
  for (i=0 ; i<n; i++ ) {
    scanf("%d", &S[i] );
    //printf("%d ", S[i] );
  }
  //printf("\n");
  scanf("%d", &q );
  for (i=0 ; i<q; i++ ) {
    scanf("%d", &T[i] );
  }

  //??????S,T????????????
  sort(n, S);
  sort(q, T);

  /*for (i=0 ; i<n; i++ ) {
    printf("%d ", S[i] );
  }
  printf("\n");
  for (i=0 ; i<q; i++ ) {
    printf("%d ", T[i] );
  }
  printf("\n");
  */

  si=0;
  for(i=0; i<q; i++){
    for(j=si; j<n ; j++){
      //printf("S=%d T=%d",j,i);
      if(S[j]==T[i]){
        count++;
        si=j+1;
        //printf("?????´\n");
        break;
      }else if(S[j]>T[i]){
        //printf("s<t\n");
        break;
      }
    }
  }
  printf("%d\n", count );
  return 0;
}

void sort(int n, int a[n]){
  int i, j, tmp;
  for (i = 1; i < n; i++) {
    tmp = a[i];
    if (a[i-1] > tmp) {
        j = i;
        do {
            a[j] = a[j-1];
            j--;
        } while (j > 0 && a[j-1] > tmp);
        a[j] = tmp;
    }
  }
}